diff --git a/build/all.py b/build/all.py
index 947a61c2c7..2fca8eee45 100755
--- a/build/all.py
+++ b/build/all.py
@@ -24,6 +24,7 @@
 import compiler
 import docs
 import gendeps
+import generateLocalizations
 import shakaBuildHelpers
 
 import os
@@ -34,6 +35,13 @@ def main(args):
       description='User facing build script for building the Shaka'
                   ' Player Project.')
 
+  parser.add_argument(
+      '--locales',
+      type=str,
+      nargs='+',
+      default=generateLocalizations.DEFAULT_LOCALES,
+      help='The list of locales to compile in (default %(default)r)')
+
   parser.add_argument(
       '--fix',
       help='Automatically fix style violations.',
@@ -59,6 +67,20 @@ def main(args):
 
   parsed_args = parser.parse_args(args)
 
+  # Make the dist/ folder, ignore errors.
+  base = shakaBuildHelpers.get_source_base()
+  try:
+    os.mkdir(os.path.join(base, 'dist'))
+  except OSError:
+    pass
+
+  # Generate localizations before running gendeps, so the output is available
+  # to the deps system.
+  # TODO(#1858): It might be time to look at a third-party build system.
+  localizations = compiler.GenerateLocalizations(parsed_args.locales)
+  if not localizations.generate(parsed_args.force):
+    return 1
+
   if gendeps.main([]) != 0:
     return 1
 
@@ -77,7 +99,6 @@ def main(args):
     return 1
 
   match = re.compile(r'.*\.less$')
-  base = shakaBuildHelpers.get_source_base()
   main_less_src = os.path.join(base, 'ui', 'controls.less')
   all_less_srcs = shakaBuildHelpers.get_all_files(
       os.path.join(base, 'ui'), match)
@@ -88,6 +109,7 @@ def main(args):
     return 1
 
   build_args_with_ui = ['--name', 'ui', '+@complete']
+  build_args_with_ui += ['--locales'] + parsed_args.locales
   build_args_without_ui = ['--name', 'compiled', '+@complete', '-@ui']
 
   if parsed_args.force:
diff --git a/build/build.py b/build/build.py
index 947d6fce76..41f904ba62 100755
--- a/build/build.py
+++ b/build/build.py
@@ -47,6 +47,7 @@
 import re
 
 import compiler
+import generateLocalizations
 import shakaBuildHelpers
 
 
@@ -170,6 +171,18 @@ def add_core(self):
       logging.error('Cannot exclude files from core')
     self.include |= core_files
 
+  def has_ui(self):
+    """Returns True if the UI library is in the build."""
+    for path in self.include:
+      if '/ui/' in path:
+        return True
+    return False
+
+  def generate_localizations(self, locales, force):
+    localizations = compiler.GenerateLocalizations(locales)
+    localizations.generate(force)
+    self.include.add(os.path.abspath(localizations.output))
+
   def parse_build(self, lines, root):
     """Parses a Build object from the given lines of commands.
 
@@ -238,11 +251,12 @@ def parse_build(self, lines, root):
 
     return True
 
-  def build_library(self, name, force, is_debug):
+  def build_library(self, name, locales, force, is_debug):
     """Builds Shaka Player using the files in |self.include|.
 
     Args:
       name: The name of the build.
+      locales: A list of strings of locale identifiers.
       force: True to rebuild, False to ignore if no changes are detected.
       is_debug: True to compile for debugging, false for release.
 
@@ -251,6 +265,8 @@ def build_library(self, name, force, is_debug):
     """
     self.add_closure()
     self.add_core()
+    if self.has_ui():
+      self.generate_localizations(locales, force)
 
     if is_debug:
       name += '.debug'
@@ -281,6 +297,13 @@ def main(args):
       description=__doc__,
       formatter_class=argparse.RawDescriptionHelpFormatter)
 
+  parser.add_argument(
+      '--locales',
+      type=str,
+      nargs='+',
+      default=generateLocalizations.DEFAULT_LOCALES,
+      help='The list of locales to compile in (requires UI, default %(default)r)')
+
   parser.add_argument(
       '--force',
       '-f',
@@ -325,10 +348,11 @@ def main(args):
     return 1
 
   name = parsed_args.name
+  locales = parsed_args.locales
   force = parsed_args.force
   is_debug = parsed_args.mode == 'debug'
 
-  if not custom_build.build_library(name, force, is_debug):
+  if not custom_build.build_library(name, locales, force, is_debug):
     return 1
 
   return 0
diff --git a/build/check.py b/build/check.py
index 718ec76993..8af3c1f318 100755
--- a/build/check.py
+++ b/build/check.py
@@ -120,6 +120,10 @@ def get(*path_components):
               get('third_party', 'language-mapping-list'))
   files.add(os.path.join(base, 'demo', 'common', 'assets.js'))
 
+  localizations = compiler.GenerateLocalizations(None)
+  localizations.generate(args.force)
+  files.add(localizations.output)
+
   closure_opts = build.common_closure_opts + build.common_closure_defines
   closure_opts += build.debug_closure_opts + build.debug_closure_defines
 
diff --git a/build/compiler.py b/build/compiler.py
index be250934b4..02304c3a64 100644
--- a/build/compiler.py
+++ b/build/compiler.py
@@ -22,6 +22,7 @@
 import shutil
 import subprocess
 
+import generateLocalizations
 import shakaBuildHelpers
 
 
@@ -354,3 +355,51 @@ def build(self, force=False):
         return False
 
     return True
+
+
+class GenerateLocalizations(object):
+  def __init__(self, locales):
+    self.locales = locales
+    self.source_files = shakaBuildHelpers.get_all_files(
+        _get_source_path('ui/locales'))
+    self.output = _get_source_path('dist/locales.js')
+
+  def _locales_changed(self):
+    # If locales is None, it means we are being called by a caller who doesn't
+    # care what locales are in use.  This is true, for example, when we are
+    # running a compiler pass over the tests.
+    if self.locales is None:
+      return False
+
+    # Find out what locales we used before.  If they have changed, we must
+    # regenerate the output.
+    last_locales = None
+    try:
+      prefix = '// LOCALES: '
+      with open(self.output, 'r') as f:
+        for line in f:
+          if line.startswith(prefix):
+            last_locales = line.replace(prefix, '').strip().split(', ')
+    except IOError:
+      # The file wasn't found or couldn't be read, so it needs to be redone.
+      return True
+
+    return set(last_locales) != set(self.locales)
+
+  def generate(self, force=False):
+    """Generate runtime localizations.
+
+    Args:
+      force: Generate the localizations even if the inputs and locales have not
+             changed.
+
+    Returns:
+      True on success; False on failure.
+    """
+
+    if (not force and not _must_build(self.output, self.source_files) and
+        not self._locales_changed()):
+      return True
+
+    generateLocalizations.main(['--locales'] + self.locales)
+    return True
diff --git a/build/gendeps.py b/build/gendeps.py
index 15efff4191..07cb08ebcc 100755
--- a/build/gendeps.py
+++ b/build/gendeps.py
@@ -30,6 +30,7 @@
     '--root_with_prefix=third_party/closure ../../../third_party/closure',
     '--root_with_prefix=third_party/language-mapping-list ' +
         '../../../third_party/language-mapping-list',
+    '--root_with_prefix=dist ../../../dist',
 ]
 
 
diff --git a/build/generateLocalizations.py b/build/generateLocalizations.py
index c1ba54ca2d..9f0ebf84ec 100755
--- a/build/generateLocalizations.py
+++ b/build/generateLocalizations.py
@@ -14,117 +14,51 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-"""Generates Javascript to load localization data.
+"""Generates Javascript to load compile-time localization data.
 
-To generate code that will load your localization data into the localization
-system you need to have your localization data in JSON format that follows the
-format:
+This reads localization data at compile-time in a flat JSON-formatted
+dictionary.  The keys are message IDs, and the values are the translated
+strings.  For example:
   {
-    "aliases": {
-      "BEST_WISHES": "ax32f",
-      "MAY_YOUR_FORGE_BURN_BRIGHT": "by984",
-      ...
-    },
-    "localizations": {
-      "elfish-woodland": {
-        "ax32f": "Merin sa haryalye alasse",
-        ...
-      },
-      "dwarfish-north": {
-        "by984": "tan menu selek lanun khun",
-        ...
-      },
-      ...
-    }
+    "BEST_WISHES": "Merin sa haryalye alasse"
   }
 
-For "aliases":
-  - The key is the alias used to associate the use-case with the entry it
-    should use.
-  - The value is the translation id used to identify the text in the locale.
-
-For "localizations":
-  - The key is the locale code.
-  - The value is a map of localization id to localized text.
-
-For all values in "localizations":
-  - The key should match a value in "aliases".
-  - The value should be the localized text.
-
-An input and an output are needed. If files are not provided for input and/or
-output, std-in and std-out will be used.
-
-Examples:
-  Read from std-in and write to std-out:
-    generate-locales.py
-  Read from input file and write to std:
-    generate-locales.py --source my-localizations.json
-  Read from input file and write to output file:
-    generate-locales.py --source my-localizations.json --output my_localizations.js
+Each locale's translations are read from a separate file.  For example, the path
+the Arabic data would be ui/locales/ar.json.
 """
 
-from __future__ import print_function
-
 import argparse
-import codecs
 import contextlib
 import json
-import string
+import os
 import sys
 
-
-_TAB_CHARACTER = '  '
-
-
-def UsesConstantSyntax(value):
-  """Check if |value| follows our style for JavaScript constants."""
-  allowed_characters = set(string.ascii_uppercase + string.digits + '_')
-
-  # This uses set difference to find any characters in |value| that don't appear
-  # in |allowed_characters|.  Then it uses boolean logic to return True for an
-  # empty set.
-  return not set(value) - allowed_characters
-
-
-def VerifyInputData(data):
-  """Verifies all the localizations and IDs line-up.
-
-  Returns:
-    A list of (warning_id, args) where warning_id is a string identifier and
-    args is a list of arguments for the warning.
-  """
-  alias_mapping = data['aliases']
-  localizations = data['localizations']
-
-  # Look for all the ids that are used across all locales. We will needs this
-  # to ensure that we have at least one alias defined for each one.
-  all_translation_ids = set()
-  for entries in localizations.values():
-    all_translation_ids.update(entries.keys())
-
-  # Get the human readable aliases for each id.
-  aliases = set(alias_mapping.keys())
-
-  warnings = []
-
-  # Check if the readable name for each id is JS-Constant compatible.
-  for alias in aliases:
-    if not UsesConstantSyntax(alias):
-      warnings.append(('bad-alias', (alias,)))
-
-  # Make sure that each translation id has an alias defined.
-  aliases_ids = set(alias_mapping.values())
-  for translation_id in all_translation_ids:
-    if translation_id not in aliases_ids:
-      warnings.append(('missing-alias', (translation_id,)))
-
-  # Check if any locales are missing entries found in other locales.
-  for locale, entries in localizations.items():
-    for translation_id in all_translation_ids:
-      if translation_id not in entries:
-        warnings.append(('missing-localization', (locale, translation_id)))
-
-  return warnings
+import shakaBuildHelpers
+
+
+_INDENTATION = '  '
+
+# These are Google's "Tier 1" languages as of April 2019.
+DEFAULT_LOCALES = [
+    'ar',
+    'de',
+    'en',
+    'en-GB',
+    'es',
+    'es-419',
+    'fr',
+    'it',
+    'ja',
+    'ko',
+    'nl',
+    'pl',
+    'pt',
+    'ru',
+    'th',
+    'tr',
+    'zh',
+    'zh-TW',
+]
 
 
 class Doc(object):
@@ -158,11 +92,11 @@ def Code(self, block):
     for line in lines:
       # Right-strip the line to avoid trailing white space. We do this on the
       # full string so that tabbing will be removed if a blank line was added.
-      new_line = (_TAB_CHARACTER * self._tab_level) + line
+      new_line = (_INDENTATION * self._tab_level) + line
       self._lines.append(new_line.rstrip())
 
-  def __str__(self):
-    return '\n'.join(self._lines)
+  def ToString(self):
+    return '\n'.join(self._lines) + '\n'
 
 
 def AsQuotedString(input_string):
@@ -182,14 +116,13 @@ def AsQuotedString(input_string):
   return "'%s'" % output_string
 
 
-def GenerateLocales(alias_mapping, localizations, class_name):
+def GenerateLocalizations(localizations, class_name):
   """Generates JavaScript code to insert the localization data.
 
   This creates a function called "apply" in the class called |class_name| that,
   when called, will insert the data from |localizations|.
 
   Args:
-    id_mappings: A map of string tag to a string JavaScript constant name.
     localizations: A map of string locale name to a map of string tag to the
       string localization.
     class_name: A string name of the class to put generated code into.
@@ -199,37 +132,27 @@ def GenerateLocales(alias_mapping, localizations, class_name):
   """
   doc = Doc()
 
-  doc.Code("""/**
- * @license
- * Copyright 2016 Google Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-""")
-
   doc.Code("""
 // !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 // This file is auto-generated. DO NOT EDIT THIS FILE. If you need to:
-//   - change which locales are in this file, update "build/locales.json"
-//   - change an entry for a specific locale, update "build/locales.json"
-//   - change anything else, update "build/generate-locales.py".
+//   - change which locales are in this file, use the --locales option in
+//     "build/all.py" or "build/build.py"
+//   - change an entry for a specific locale, update "ui/locales/"
+//   - change anything else, update "build/generateLocalizations.py".
 //
-// To regenerate this file, run "build/generate-locales.py".
+// To regenerate this file, run "build/generateLocalizations.py".
 // !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 """)
 
+  # Insert a comment that the build scripts will read to determine the freshness
+  # of this output.  This will be compared against a list of locales in the
+  # current build to decide if the output needs to be regenerated.
+  # DO NOT change the formatting here without also updating the "compiler.py"
+  # module and the "GenerateLocalizations" class's "_locales_changed" method.
+  locale_list_string = ', '.join(sorted(localizations.keys()))
+  doc.Code('// LOCALES: %s' % locale_list_string)
+
   doc.Code("goog.provide('%s');" % class_name)
-  doc.Code("goog.provide('%s.Ids');" % class_name)
   doc.Code("goog.require('shaka.ui.Localization');")
 
   doc.Code("""
@@ -241,11 +164,12 @@ def GenerateLocales(alias_mapping, localizations, class_name):
  * each insert).
  *
  * @param {!shaka.ui.Localization} localization
- */
-""")
+ */""")
 
   doc.Code('%s.apply = function(localization) {' % class_name)
 
+  message_ids = set()
+
   # Go through the locales in sorted order so that we will be consistent between
   # runs.
   for locale in sorted(localizations.keys()):
@@ -259,6 +183,7 @@ def GenerateLocales(alias_mapping, localizations, class_name):
         # Make sure that we sort by the localization keys so that they will
         # always be in the same order.
         for key, value in sorted(localization.items()):
+          message_ids.add(key)
           quoted_key = AsQuotedString(key)
           quoted_value = AsQuotedString(value)
           doc.Code('[%s, %s],' % (quoted_key, quoted_value))
@@ -267,49 +192,51 @@ def GenerateLocales(alias_mapping, localizations, class_name):
 
   doc.Code('};')  # Close the function.
 
-  # Convert the map to an array with the key and value reversed so
-  # that we can sort them based on the alias.
-  constants = []
-  for alias, translation_id in alias_mapping.items():
-    constants.append((alias, translation_id))
-  constants.sort()
-
-  for alias, translation_id in constants:
-    doc.Code('')  # Make sure we have a blank line before each constant.
-    doc.Code('/** @const {string} */')
-    doc.Code('%s.Ids.%s = %s;' % (class_name,
-                                  alias,
-                                  AsQuotedString(translation_id)))
-
-  doc.Code('')  # Need blank line at the end of the file
+  doc.Code("""
+/**
+ * @enum {string}
+ * @const
+ */
+%s.Ids = {""" % class_name)
+  for message_id in message_ids:
+    doc.Code('  %s: %s,' % (message_id, AsQuotedString(message_id)))
+  doc.Code('};')
 
-  return doc
+  return doc.ToString()
 
 
 def CreateParser():
   """Create the argument parser for this application."""
+  base = shakaBuildHelpers.get_source_base()
+
   parser = argparse.ArgumentParser(
       description=__doc__,
       formatter_class=argparse.RawDescriptionHelpFormatter)
 
+  parser.add_argument(
+      '--locales',
+      type=str,
+      nargs='+',
+      default=DEFAULT_LOCALES,
+      help='The list of locales to compile in (default %(default)r)')
+
   parser.add_argument(
       '--source',
-      dest='source',
       type=str,
-      help='The file path for JSON input. (default: std in).')
+      default=os.path.join(base, 'ui', 'locales'),
+      help='The folder path for JSON inputs')
 
   parser.add_argument(
       '--output',
-      dest='output',
       type=str,
-      help='The file path for JavaScript output (default: std out).')
+      default=os.path.join(base, 'dist', 'locales.js'),
+      help='The file path for JavaScript output')
 
   parser.add_argument(
       '--class-name',
-      dest='class_name',
       type=str,
-      help='The fully qualified class name for the JavaScript output',
-      default='shaka.ui.Locales')
+      default='shaka.ui.Locales',
+      help='The fully qualified class name for the JavaScript output')
 
   return parser
 
@@ -318,24 +245,17 @@ def main(args):
   parser = CreateParser()
   args = parser.parse_args(args)
 
-  if args.source:
-    with open(args.source, 'r') as f:
-      blob = json.load(f)
-  else:
-    if sys.stdin.isatty():
-      sys.stderr.write('Reading input JSON from stdin...\n')
-    blob = json.load(sys.stdin)
-
-  for warning_id, warning_args in VerifyInputData(blob):
-    sys.stderr.write('WARNING: %s %s\n' % (warning_id, warning_args))
+  combined_localizations = {}
+  for locale in args.locales:
+    path = os.path.join(args.source, locale + '.json')
+    with open(path, 'rb') as f:
+      combined_localizations[locale] = json.load(f)
 
-  doc = GenerateLocales(blob['aliases'], blob['localizations'], args.class_name)
+  doc = GenerateLocalizations(combined_localizations, args.class_name)
+  with open(args.output, 'wb') as f:
+    f.write(doc.encode('utf-8'))
 
-  if args.output:
-    with codecs.open(args.output, 'w', 'utf-8') as f:
-      f.write(unicode(doc))
-  else:
-    sys.stdout.write(unicode(doc))
+  return args.output
 
 
 if __name__ == '__main__':
diff --git a/build/locales.json b/build/locales.json
deleted file mode 100644
index ada07d4e73..0000000000
--- a/build/locales.json
+++ /dev/null
@@ -1,579 +0,0 @@
-{
-  "aliases":{
-    "ARIA_LABEL_BACK":"1077325112364709655",
-    "ARIA_LABEL_CAPTIONS":"1911090580951495029",
-    "ARIA_LABEL_CAST":"7071612439610534706",
-    "ARIA_LABEL_EXIT_FULL_SCREEN":"6161306839322897077",
-    "ARIA_LABEL_FAST_FORWARD":"1774834209035716827",
-    "ARIA_LABEL_FULL_SCREEN":"8345190086337560158",
-    "ARIA_LABEL_LANGUAGE":"3278592358864783064",
-    "ARIA_LABEL_LIVE":"3045980486001972586",
-    "ARIA_LABEL_MORE_SETTINGS":"4388316720828367903",
-    "ARIA_LABEL_MUTE":"5963689277976480680",
-    "ARIA_LABEL_PAUSE":"9042260521669277115",
-    "ARIA_LABEL_ENTER_PICTURE_IN_PICTURE": "4242938254936928940",
-    "ARIA_LABEL_EXIT_PICTURE_IN_PICTURE": "6614181658619787283",
-    "ARIA_LABEL_PLAY":"836055097473758014",
-    "ARIA_LABEL_RESOLUTION":"6073266792045231479",
-    "ARIA_LABEL_REWIND":"1142734805932039923",
-    "ARIA_LABEL_SEEK":"5553522235935533682",
-    "ARIA_LABEL_UNMUTE":"2023925063728908356",
-    "ARIA_LABEL_VOLUME":"1050953507607739202",
-    "LABEL_AUTO_QUALITY":"4259064532355692191",
-    "LABEL_CAPTIONS":"1911090580951495029",
-    "LABEL_CAPTIONS_OFF":"8145129506114534451",
-    "LABEL_CAST":"7071612439610534706",
-    "LABEL_LANGUAGE":"3278592358864783064",
-    "LABEL_LIVE":"3045980486001972586",
-    "LABEL_MULTIPLE_LANGUAGES":"411375375680850814",
-    "LABEL_NOT_APPLICABLE":"5146287486336231188",
-    "LABEL_NOT_CASTING":"8145129506114534451",
-    "LABEL_PICTURE_IN_PICTURE":"622115170869907732",
-    "LABEL_PICTURE_IN_PICTURE_ON":"142853231704504146",
-    "LABEL_PICTURE_IN_PICTURE_OFF":"8145129506114534451",
-    "LABEL_RESOLUTION":"6073266792045231479",
-    "LABEL_UNKNOWN_LANGUAGE":"298626259350585300"
-  },
-  "localizations":{  
-      "ar":{  
-         "1077325112364709655":"رجوع",
-         "8345190086337560158":"ملء الشاشة",
-         "6161306839322897077":"إنهاء وضع ملء الشاشة",
-         "1774834209035716827":"تقديم سريع",
-         "3045980486001972586":"مباشر",
-         "5963689277976480680":"كتم الصوت",
-         "1911090580951495029":"الترجمة",
-         "9042260521669277115":"إيقاف مؤقت",
-         "4242938254936928940":"الدخول في وضع \"نافذة ضمن نافذة\"",
-         "6614181658619787283":"الخروج من وضع \"نافذة ضمن نافذة\"",
-         "836055097473758014":"تشغيل",
-         "1142734805932039923":"إرجاع",
-         "4388316720828367903":"إعدادات إضافية",
-         "6073266792045231479":"",
-         "5553522235935533682":"شريط تمرير البحث",
-         "7071612439610534706":"إرسال...",
-         "2023925063728908356":"إلغاء كتم الصوت",
-         "1050953507607739202":"الحجم",
-         "4259064532355692191":"تلقائي",
-         "8145129506114534451":"إيقاف",
-         "3278592358864783064":"اللغة",
-         "622115170869907732":"نافذة ضمن النافذة",
-         "142853231704504146":"تشغيل",
-         "298626259350585300":"غير معروفة",
-         "5146287486336231188":"غير سارٍ"
-      },
-      "de":{  
-         "1077325112364709655":"Zurück",
-         "8345190086337560158":"Vollbild",
-         "6161306839322897077":"Vollbildmodus beenden",
-         "1774834209035716827":"Vorspulen",
-         "3045980486001972586":"Live",
-         "5963689277976480680":"Stummschalten",
-         "1911090580951495029":"Untertitel",
-         "9042260521669277115":"Pausieren",
-         "4242938254936928940":"Bild-im-Bild-Modus aktivieren",
-         "6614181658619787283":"Bild-im-Bild-Modus beenden",
-         "836055097473758014":"Wiedergeben",
-         "1142734805932039923":"Zurückspulen",
-         "4388316720828367903":"Weitere Einstellungen",
-         "6073266792045231479":"Auflösung",
-         "5553522235935533682":"Schieberegler für Suche",
-         "7071612439610534706":"Streamen…",
-         "2023925063728908356":"Stummschaltung aufheben",
-         "1050953507607739202":"Lautstärke",
-         "4259064532355692191":"Automatisch",
-         "8145129506114534451":"Aus",
-         "3278592358864783064":"Sprache",
-         "622115170869907732":"Bild-in-Bild",
-         "142853231704504146":"An",
-         "298626259350585300":"Unbekannt",
-         "5146287486336231188":"Nicht zutreffend"
-      },
-      "en-GB":{  
-         "1077325112364709655":"Back",
-         "8345190086337560158":"Full screen",
-         "6161306839322897077":"Exit full screen",
-         "1774834209035716827":"Fast-forward",
-         "3045980486001972586":"Live",
-         "5963689277976480680":"Mute",
-         "1911090580951495029":"Captions",
-         "9042260521669277115":"Pause",
-         "4242938254936928940":"enter picture-in-picture",
-         "6614181658619787283":"exit picture-in-picture",
-         "836055097473758014":"Play",
-         "1142734805932039923":"Rewind",
-         "4388316720828367903":"More settings",
-         "6073266792045231479":"Resolution",
-         "5553522235935533682":"Seek slider",
-         "7071612439610534706":"Cast...",
-         "2023925063728908356":"Unmute",
-         "1050953507607739202":"volume",
-         "4259064532355692191":"Auto",
-         "8145129506114534451":"Off",
-         "3278592358864783064":"Language",
-         "622115170869907732":"Picture in Picture",
-         "142853231704504146":"on",
-         "298626259350585300":"Unknown",
-         "5146287486336231188":"Not applicable"
-      },
-      "en":{  
-         "1077325112364709655":"Back",
-         "8345190086337560158":"Full screen",
-         "6161306839322897077":"Exit full screen",
-         "1774834209035716827":"Fast-forward",
-         "3045980486001972586":"Live",
-         "5963689277976480680":"Mute",
-         "1911090580951495029":"Captions",
-         "9042260521669277115":"Pause",
-         "4242938254936928940":"enter picture-in-picture",
-         "6614181658619787283":"exit picture-in-picture",
-         "836055097473758014":"Play",
-         "1142734805932039923":"Rewind",
-         "4388316720828367903":"More settings",
-         "6073266792045231479":"Resolution",
-         "5553522235935533682":"Seek slider",
-         "7071612439610534706":"Cast...",
-         "2023925063728908356":"Unmute",
-         "1050953507607739202":"volume",
-         "4259064532355692191":"Auto",
-         "8145129506114534451":"Off",
-         "3278592358864783064":"Language",
-         "622115170869907732":"Picture in Picture",
-         "142853231704504146":"on",
-         "298626259350585300":"Unknown",
-         "5146287486336231188":"Not applicable"
-      },
-      "es":{  
-         "1077325112364709655":"Atrás",
-         "8345190086337560158":"Pantalla completa",
-         "6161306839322897077":"Salir del modo de pantalla completa",
-         "1774834209035716827":"Avance rápido",
-         "3045980486001972586":"En directo",
-         "5963689277976480680":"Silenciar",
-         "1911090580951495029":"Subtítulos",
-         "9042260521669277115":"Pausa",
-         "4242938254936928940":"abrir el modo imagen en imagen",
-         "6614181658619787283":"salir del modo imagen en imagen",
-         "836055097473758014":"Reproducir",
-         "1142734805932039923":"Retroceder",
-         "4388316720828367903":"Más ajustes",
-         "6073266792045231479":"Resolución",
-         "5553522235935533682":"Barra deslizante de búsqueda",
-         "7071612439610534706":"Reparto...",
-         "2023925063728908356":"Activar sonido",
-         "1050953507607739202":"volumen",
-         "4259064532355692191":"Automática",
-         "8145129506114534451":"No",
-         "3278592358864783064":"Idioma",
-         "622115170869907732":"Imagen en imagen",
-         "142853231704504146":"activado",
-         "298626259350585300":"Desconocido",
-         "5146287486336231188":"No aplicable"
-      },
-      "es-419":{  
-         "1077325112364709655":"Atrás",
-         "8345190086337560158":"Pantalla completa",
-         "6161306839322897077":"Salir de pantalla completa",
-         "1774834209035716827":"Avance rápido",
-         "3045980486001972586":"En vivo",
-         "5963689277976480680":"Silenciar",
-         "1911090580951495029":"Subtítulos",
-         "9042260521669277115":"Detener",
-         "4242938254936928940":"ingresar al modo de pantalla en pantalla",
-         "6614181658619787283":"salir del modo de pantalla en pantalla",
-         "836055097473758014":"Jugar",
-         "1142734805932039923":"Retroceder",
-         "4388316720828367903":"Más opciones de configuración",
-         "6073266792045231479":"Resolución",
-         "5553522235935533682":"Barra deslizante de búsqueda",
-         "7071612439610534706":"Transmitir…",
-         "2023925063728908356":"Activar sonido",
-         "1050953507607739202":"volumen",
-         "4259064532355692191":"Auto",
-         "8145129506114534451":"Desactivado",
-         "3278592358864783064":"Idioma",
-         "622115170869907732":"Pantalla en pantalla",
-         "142853231704504146":"activado",
-         "298626259350585300":"Desconocido",
-         "5146287486336231188":"No aplicable"
-      },
-      "fr":{  
-         "1077325112364709655":"Retour",
-         "8345190086337560158":"Plein écran",
-         "6161306839322897077":"Quitter le mode plein écran",
-         "1774834209035716827":"Avance rapide",
-         "3045980486001972586":"En direct",
-         "5963689277976480680":"Désactiver le son",
-         "1911090580951495029":"Sous-titres",
-         "9042260521669277115":"Mettre en veille",
-         "4242938254936928940":"utiliser le mode PIP",
-         "6614181658619787283":"quitter le mode PIP",
-         "836055097473758014":"Lire",
-         "1142734805932039923":"Retour arrière",
-         "4388316720828367903":"Autres paramètres",
-         "6073266792045231479":"Résolution",
-         "5553522235935533682":"Barre de recherche",
-         "7071612439610534706":"Caster sur…",
-         "2023925063728908356":"Activer le son",
-         "1050953507607739202":"volume",
-         "4259064532355692191":"Auto",
-         "8145129506114534451":"Désactivée",
-         "3278592358864783064":"Langue",
-         "622115170869907732":"Picture-in-picture",
-         "142853231704504146":"activé",
-         "298626259350585300":"Inconnue",
-         "5146287486336231188":"Non applicable"
-      },
-      "it":{  
-         "1077325112364709655":"Indietro",
-         "8345190086337560158":"Schermo intero",
-         "6161306839322897077":"Esci dalla modalità a schermo intero",
-         "1774834209035716827":"Avanti veloce",
-         "3045980486001972586":"Dal vivo",
-         "5963689277976480680":"Disattiva audio",
-         "1911090580951495029":"Sottotitoli",
-         "9042260521669277115":"Metti in pausa",
-         "4242938254936928940":"attiva picture in picture",
-         "6614181658619787283":"esci da picture in picture",
-         "836055097473758014":"Riproduci",
-         "1142734805932039923":"Riavvolgi",
-         "4388316720828367903":"Altre impostazioni",
-         "6073266792045231479":"Risoluzione",
-         "5553522235935533682":"Dispositivo di scorrimento",
-         "7071612439610534706":"Trasmetti…",
-         "2023925063728908356":"Riattiva audio",
-         "1050953507607739202":"volume",
-         "4259064532355692191":"Auto",
-         "8145129506114534451":"Disattivato",
-         "3278592358864783064":"Lingua",
-         "622115170869907732":"Picture in picture",
-         "142853231704504146":"on",
-         "298626259350585300":"Sconosciuto",
-         "5146287486336231188":"Non applicable"
-      },
-      "ja":{  
-         "1077325112364709655":"戻る",
-         "8345190086337560158":"全画面",
-         "6161306839322897077":"全画面モードの終了",
-         "1774834209035716827":"早送り",
-         "3045980486001972586":"ライブ",
-         "5963689277976480680":"ミュート",
-         "1911090580951495029":"字幕",
-         "9042260521669277115":"一時停止",
-         "4242938254936928940":"ピクチャー イン ピクチャーを開始します",
-         "6614181658619787283":"ピクチャー イン ピクチャーを終了します",
-         "836055097473758014":"再生",
-         "1142734805932039923":"巻き戻し",
-         "4388316720828367903":"その他の設定",
-         "6073266792045231479":"解像度",
-         "5553522235935533682":"シーク バー",
-         "7071612439610534706":"キャスト...",
-         "2023925063728908356":"ミュート解除",
-         "1050953507607739202":"音量",
-         "4259064532355692191":"自動",
-         "8145129506114534451":"オフ",
-         "3278592358864783064":"言語",
-         "622115170869907732":"ピクチャー イン ピクチャー",
-         "142853231704504146":"オン",
-         "298626259350585300":"不明",
-         "5146287486336231188":"--"
-      },
-      "ko":{  
-         "1077325112364709655":"뒤로",
-         "8345190086337560158":"전체화면",
-         "6161306839322897077":"전체화면 종료",
-         "1774834209035716827":"빨리감기",
-         "3045980486001972586":"라이브",
-         "5963689277976480680":"음소거",
-         "1911090580951495029":"자막",
-         "9042260521669277115":"일시중지",
-         "4242938254936928940":"PIP 모드 시작",
-         "6614181658619787283":"PIP 모드 종료",
-         "836055097473758014":"재생",
-         "1142734805932039923":"되감기",
-         "4388316720828367903":"설정 더보기",
-         "6073266792045231479":"해상도",
-         "5553522235935533682":"탐색 슬라이더",
-         "7071612439610534706":"전송...",
-         "2023925063728908356":"음소거 해제",
-         "1050953507607739202":"볼륨",
-         "4259064532355692191":"자동",
-         "8145129506114534451":"사용 안함",
-         "3278592358864783064":"언어",
-         "622115170869907732":"PIP 모드",
-         "142853231704504146":"사용",
-         "298626259350585300":"알 수 없음",
-         "5146287486336231188":"해당 사항 없음"
-      },
-      "nl":{  
-         "1077325112364709655":"Terug",
-         "8345190086337560158":"Volledig scherm",
-         "6161306839322897077":"Volledig scherm afsluiten",
-         "1774834209035716827":"Vooruitspoelen",
-         "3045980486001972586":"Live",
-         "5963689277976480680":"Dempen",
-         "1911090580951495029":"Ondertiteling",
-         "9042260521669277115":"Onderbreken",
-         "4242938254936928940":"scherm-in-scherm openen",
-         "6614181658619787283":"scherm-in-scherm afsluiten",
-         "836055097473758014":"Afspelen",
-         "1142734805932039923":"Terugspoelen",
-         "4388316720828367903":"Meer instellingen",
-         "6073266792045231479":"Resolutie",
-         "5553522235935533682":"Zoekschuifbalk",
-         "7071612439610534706":"Casten...",
-         "2023925063728908356":"Dempen opheffen",
-         "1050953507607739202":"volume",
-         "4259064532355692191":"Automatisch",
-         "8145129506114534451":"Uit",
-         "3278592358864783064":"Taal",
-         "622115170869907732":"Scherm-in-scherm",
-         "142853231704504146":"aan",
-         "298626259350585300":"Onbekend",
-         "5146287486336231188":"Niet van toepassing"
-      },
-      "pl":{  
-         "1077325112364709655":"Wstecz",
-         "8345190086337560158":"Pełny ekran",
-         "6161306839322897077":"Zamknij pełny ekran",
-         "1774834209035716827":"Przewiń do przodu",
-         "3045980486001972586":"Na żywo",
-         "5963689277976480680":"Wycisz",
-         "1911090580951495029":"Napisy",
-         "9042260521669277115":"Wstrzymaj",
-         "4242938254936928940":"włącz tryb obrazu w obrazie",
-         "6614181658619787283":"wyłącz tryb obrazu w obrazie",
-         "836055097473758014":"Odtwarzaj",
-         "1142734805932039923":"Przewiń do tyłu",
-         "4388316720828367903":"Więcej ustawień",
-         "6073266792045231479":"Rozdzielczość",
-         "5553522235935533682":"Suwak przewijania",
-         "7071612439610534706":"Prześlij...",
-         "2023925063728908356":"Wyłącz wyciszenie",
-         "1050953507607739202":"głośność",
-         "4259064532355692191":"Automatyczna",
-         "8145129506114534451":"Wyłączone",
-         "3278592358864783064":"Język",
-         "622115170869907732":"Obraz w obrazie",
-         "142853231704504146":"wł.",
-         "298626259350585300":"Nieznane",
-         "5146287486336231188":"Nie dotyczy"
-      },
-      "pt-BR":{  
-         "1077325112364709655":"Voltar",
-         "8345190086337560158":"Tela inteira",
-         "6161306839322897077":"Sair da tela inteira",
-         "1774834209035716827":"Avançar",
-         "3045980486001972586":"Ao vivo",
-         "5963689277976480680":"Desativar som",
-         "1911090580951495029":"Legendas ocultas",
-         "9042260521669277115":"Pausar",
-         "4242938254936928940":"entrar no modo picture-in-picture",
-         "6614181658619787283":"sair de picture-in-picture",
-         "836055097473758014":"Reproduzir",
-         "1142734805932039923":"Retroceder",
-         "4388316720828367903":"Mais configurações",
-         "6073266792045231479":"Resolução",
-         "5553522235935533682":"Botão deslizante de busca",
-         "7071612439610534706":"Elenco...",
-         "2023925063728908356":"Ativar som",
-         "1050953507607739202":"volume",
-         "4259064532355692191":"Automático",
-         "8145129506114534451":"Desativado",
-         "3278592358864783064":"Idioma",
-         "622115170869907732":"Picture-in-picture",
-         "142853231704504146":"ativado",
-         "298626259350585300":"Desconhecido",
-         "5146287486336231188":"Não aplicável"
-      },
-      "pt-PT":{  
-         "1077325112364709655":"Anterior",
-         "8345190086337560158":"Ecrã inteiro",
-         "6161306839322897077":"Sair do ecrã inteiro",
-         "1774834209035716827":"Avançar",
-         "3045980486001972586":"Em direto",
-         "5963689277976480680":"Desativar o som",
-         "1911090580951495029":"Legendas",
-         "9042260521669277115":"Colocar em pausa",
-         "4242938254936928940":"entrar no modo ecrã no ecrã",
-         "6614181658619787283":"sair do modo ecrã no ecrã",
-         "836055097473758014":"Reproduzir",
-         "1142734805932039923":"Recuar",
-         "4388316720828367903":"Mais definições",
-         "6073266792045231479":"Resolução",
-         "5553522235935533682":"Controlo de deslize da procura",
-         "7071612439610534706":"Transmitir...",
-         "2023925063728908356":"Reativar o som",
-         "1050953507607739202":"volume",
-         "4259064532355692191":"Automático",
-         "8145129506114534451":"Desativado",
-         "3278592358864783064":"Idioma",
-         "622115170869907732":"Ecrã no ecrã",
-         "142853231704504146":"ativado",
-         "298626259350585300":"Desconhecida",
-         "5146287486336231188":"Não aplicável"
-      },
-      "ru":{  
-         "1077325112364709655":"Назад",
-         "8345190086337560158":"Во весь экран",
-         "6161306839322897077":"Выход из полноэкранного режима",
-         "1774834209035716827":"Перемотать вперед",
-         "3045980486001972586":"В эфире",
-         "5963689277976480680":"Отключить звук",
-         "1911090580951495029":"Субтитры",
-         "9042260521669277115":"Приостановить",
-         "4242938254936928940":"включить режим \"Картинка в картинке\"",
-         "6614181658619787283":"выйти из режима \"Картинка в картинке\"",
-         "836055097473758014":"Смотреть",
-         "1142734805932039923":"Перемотать назад",
-         "4388316720828367903":"Дополнительные настройки",
-         "6073266792045231479":"Разрешение",
-         "5553522235935533682":"Ползунок поиска",
-         "7071612439610534706":"Хромкаст",
-         "2023925063728908356":"Включить звук",
-         "1050953507607739202":"громкость",
-         "4259064532355692191":"Автонастройка",
-         "8145129506114534451":"Выкл.",
-         "3278592358864783064":"Язык",
-         "622115170869907732":"Картинка в картинке",
-         "142853231704504146":"ВКЛ",
-         "298626259350585300":"Неизвестно",
-         "5146287486336231188":"Неприменимо"
-      },
-      "th":{  
-         "1077325112364709655":"กลับ",
-         "8345190086337560158":"เต็มหน้าจอ",
-         "6161306839322897077":"ออกจากโหมดเต็มหน้าจอ",
-         "1774834209035716827":"กรอไปข้างหน้า",
-         "3045980486001972586":"สด",
-         "5963689277976480680":"ปิดเสียง",
-         "1911090580951495029":"คำอธิบายวิดีโอ",
-         "9042260521669277115":"หยุดชั่วคราว",
-         "4242938254936928940":"เข้าสู่การแสดงภาพซ้อนภาพ",
-         "6614181658619787283":"ออกจากการแสดงภาพซ้อนภาพ",
-         "836055097473758014":"เล่น",
-         "1142734805932039923":"กรอกลับ",
-         "4388316720828367903":"การตั้งค่าเพิ่มเติม",
-         "6073266792045231479":"ความละเอียด",
-         "5553522235935533682":"แถบเลื่อนค้นหา",
-         "7071612439610534706":"แคสต์...",
-         "2023925063728908356":"เปิดเสียง",
-         "1050953507607739202":"ระดับเสียง",
-         "4259064532355692191":"อัตโนมัติ",
-         "8145129506114534451":"ปิด",
-         "3278592358864783064":"ภาษา",
-         "622115170869907732":"การแสดงภาพซ้อนภาพ",
-         "142853231704504146":"เปิด",
-         "298626259350585300":"ไม่ทราบ",
-         "5146287486336231188":"ไม่เกี่ยวข้อง"
-      },
-      "tr":{  
-         "1077325112364709655":"Geri",
-         "8345190086337560158":"Tam ekran",
-         "6161306839322897077":"Tam ekrandan çık",
-         "1774834209035716827":"İleri sar",
-         "3045980486001972586":"Canlı",
-         "5963689277976480680":"Sesi kapat",
-         "1911090580951495029":"Altyazılar",
-         "9042260521669277115":"Duraklat",
-         "4242938254936928940":"pencere içinde pencere moduna gir",
-         "6614181658619787283":"pencere içinde pencere modundan çıkın",
-         "836055097473758014":"Oynat",
-         "1142734805932039923":"Geri sar",
-         "4388316720828367903":"Diğer ayarlar",
-         "6073266792045231479":"Çözünürlük",
-         "5553522235935533682":"Arama kaydırma çubuğu",
-         "7071612439610534706":"Yayınla...",
-         "2023925063728908356":"Sesi aç",
-         "1050953507607739202":"ses düzeyi",
-         "4259064532355692191":"Otomatik",
-         "8145129506114534451":"Kapalı",
-         "3278592358864783064":"Dil",
-         "622115170869907732":"Pencere içinde Pencere",
-         "142853231704504146":"açık",
-         "298626259350585300":"Bilinmiyor",
-         "5146287486336231188":"Kullanılmıyor"
-      },
-      "zh-HK":{  
-         "1077325112364709655":"返回",
-         "8345190086337560158":"全螢幕",
-         "6161306839322897077":"結束全螢幕",
-         "1774834209035716827":"快轉",
-         "3045980486001972586":"直播",
-         "5963689277976480680":"靜音",
-         "1911090580951495029":"字幕",
-         "9042260521669277115":"暫停",
-         "4242938254936928940":"進入畫中畫",
-         "6614181658619787283":"退出畫中畫",
-         "836055097473758014":"播放",
-         "1142734805932039923":"倒帶",
-         "4388316720828367903":"更多設定",
-         "6073266792045231479":"",
-         "5553522235935533682":"搜尋滑桿",
-         "7071612439610534706":"投放…",
-         "2023925063728908356":"解除靜音",
-         "1050953507607739202":"音量",
-         "4259064532355692191":"自動",
-         "8145129506114534451":"未選取",
-         "3278592358864783064":"語言",
-         "622115170869907732":"畫中畫",
-         "142853231704504146":"",
-         "298626259350585300":"不明",
-         "5146287486336231188":"不適用"
-      },
-      "zh-CN":{  
-         "1077325112364709655":"返回",
-         "8345190086337560158":"全屏",
-         "6161306839322897077":"退出全屏",
-         "1774834209035716827":"快进",
-         "3045980486001972586":"直播",
-         "5963689277976480680":"静音",
-         "1911090580951495029":"字幕",
-         "9042260521669277115":"暂停",
-         "4242938254936928940":"进入“画中画”模式",
-         "6614181658619787283":"退出“画中画”模式",
-         "836055097473758014":"播放",
-         "1142734805932039923":"快退",
-         "4388316720828367903":"更多设置",
-         "6073266792045231479":"分辨率",
-         "5553522235935533682":"播放滑块",
-         "7071612439610534706":"投射…",
-         "2023925063728908356":"取消静音",
-         "1050953507607739202":"音量",
-         "4259064532355692191":"自动",
-         "8145129506114534451":"关闭",
-         "3278592358864783064":"语言",
-         "622115170869907732":"画中画",
-         "142853231704504146":"开启",
-         "298626259350585300":"未知",
-         "5146287486336231188":"不適用"
-      },
-      "zh-TW":{  
-         "1077325112364709655":"返回",
-         "8345190086337560158":"全螢幕",
-         "6161306839322897077":"結束全螢幕",
-         "1774834209035716827":"快轉",
-         "3045980486001972586":"直播",
-         "5963689277976480680":"靜音",
-         "1911090580951495029":"字幕",
-         "9042260521669277115":"暫停",
-         "4242938254936928940":"進入子母畫面",
-         "6614181658619787283":"離開子母畫面",
-         "836055097473758014":"播放",
-         "1142734805932039923":"倒轉",
-         "4388316720828367903":"更多設定",
-         "6073266792045231479":"解析度",
-         "5553522235935533682":"搜尋滑桿",
-         "7071612439610534706":"投放…",
-         "2023925063728908356":"解除靜音",
-         "1050953507607739202":"音量",
-         "4259064532355692191":"自動",
-         "8145129506114534451":"關閉",
-         "3278592358864783064":"語言",
-         "622115170869907732":"子母畫面",
-         "142853231704504146":"開啟",
-         "298626259350585300":"未知",
-         "5146287486336231188":"不適用"
-      }
-   }
-}
diff --git a/build/types/ui b/build/types/ui
index f11ff91577..69f1300dbb 100644
--- a/build/types/ui
+++ b/build/types/ui
@@ -12,7 +12,6 @@
 +../../ui/fullscreen_button.js
 +../../ui/language_utils.js
 +../../ui/localization.js
-+../../ui/locales.js
 +../../ui/mute_button.js
 +../../ui/overflow_menu.js
 +../../ui/pip_button.js
diff --git a/karma.conf.js b/karma.conf.js
index edaf6e16e7..75ed643c09 100644
--- a/karma.conf.js
+++ b/karma.conf.js
@@ -114,6 +114,7 @@ module.exports = function(config) {
       {pattern: 'third_party/language-mapping-list/**/*.js', included: false},
       {pattern: 'test/test/assets/*', included: false},
       {pattern: 'dist/shaka-player.ui.js', included: false},
+      {pattern: 'dist/locales.js', included: false},
       {pattern: 'node_modules/**/*.js', included: false},
     ],
 
diff --git a/ui/audio_language_selection.js b/ui/audio_language_selection.js
index 081ef7fa0f..2bed2495a3 100644
--- a/ui/audio_language_selection.js
+++ b/ui/audio_language_selection.js
@@ -188,13 +188,13 @@ shaka.ui.AudioLanguageSelection = class extends shaka.ui.Element {
     const LocIds = shaka.ui.Locales.Ids;
 
     this.backFromLanguageButton_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
-        this.localization.resolve(LocIds.ARIA_LABEL_BACK));
+        this.localization.resolve(LocIds.BACK));
     this.languagesButton_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
-        this.localization.resolve(LocIds.ARIA_LABEL_LANGUAGE));
+        this.localization.resolve(LocIds.LANGUAGE));
     this.languageNameSpan_.textContent =
-      this.localization.resolve(LocIds.LABEL_LANGUAGE);
+        this.localization.resolve(LocIds.LANGUAGE);
     this.backFromLanguageSpan_.textContent =
-      this.localization.resolve(LocIds.LABEL_LANGUAGE);
+        this.localization.resolve(LocIds.LANGUAGE);
   }
 };
 
diff --git a/ui/cast_button.js b/ui/cast_button.js
index fb58edb6a1..d9f291986b 100644
--- a/ui/cast_button.js
+++ b/ui/cast_button.js
@@ -147,7 +147,7 @@ shaka.ui.CastButton = class extends shaka.ui.Element {
           this.castProxy_.receiverName();
     } else {
       this.castCurrentSelectionSpan_.textContent =
-          this.localization.resolve(shaka.ui.Locales.Ids.LABEL_NOT_CASTING);
+          this.localization.resolve(shaka.ui.Locales.Ids.OFF);
     }
   }
 
@@ -159,9 +159,9 @@ shaka.ui.CastButton = class extends shaka.ui.Element {
     const LocIds = shaka.ui.Locales.Ids;
 
     this.castButton_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
-        this.localization.resolve(LocIds.ARIA_LABEL_CAST));
+        this.localization.resolve(LocIds.CAST));
     this.castNameSpan_.textContent =
-      this.localization.resolve(LocIds.LABEL_CAST);
+        this.localization.resolve(LocIds.CAST);
 
     // If we're not casting, string "not casting" will be displayed,
     // which needs localization.
diff --git a/ui/controls.js b/ui/controls.js
index 2ae8d9b43b..873dad9b03 100644
--- a/ui/controls.js
+++ b/ui/controls.js
@@ -448,13 +448,12 @@ shaka.ui.Controls.prototype.updateLocalizedStrings_ = function() {
 
   if (this.seekBar_) {
     this.seekBar_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
-          this.localization_.resolve(LocIds.ARIA_LABEL_SEEK));
+          this.localization_.resolve(LocIds.SEEK));
   }
 
   // Localize state-dependant labels
   const makePlayNotPause = this.video_.paused && !this.isSeeking_;
-  const playButtonAriaLabelId = makePlayNotPause ? LocIds.ARIA_LABEL_PLAY :
-                                                   LocIds.ARIA_LABEL_PAUSE;
+  const playButtonAriaLabelId = makePlayNotPause ? LocIds.PLAY : LocIds.PAUSE;
   this.playButton_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
       this.localization_.resolve(playButtonAriaLabelId));
 };
@@ -893,11 +892,11 @@ shaka.ui.Controls.prototype.onPlayStateChange_ = function() {
   if (this.enabled_ && this.video_.paused && !this.isSeeking_) {
     this.playButton_.setAttribute('icon', 'play');
     this.playButton_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
-      this.localization_.resolve(shaka.ui.Locales.Ids.ARIA_LABEL_PLAY));
+      this.localization_.resolve(shaka.ui.Locales.Ids.PLAY));
   } else {
     this.playButton_.setAttribute('icon', 'pause');
     this.playButton_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
-      this.localization_.resolve(shaka.ui.Locales.Ids.ARIA_LABEL_PAUSE));
+      this.localization_.resolve(shaka.ui.Locales.Ids.PAUSE));
   }
 };
 
diff --git a/ui/fast_forward_button.js b/ui/fast_forward_button.js
index 7c84412d2b..bd7cefd314 100644
--- a/ui/fast_forward_button.js
+++ b/ui/fast_forward_button.js
@@ -65,8 +65,7 @@ shaka.ui.FastForwardButton = class extends shaka.ui.Element {
    */
   updateAriaLabel_() {
     this.button_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
-        this.localization.resolve(
-          shaka.ui.Locales.Ids.ARIA_LABEL_FAST_FORWARD));
+        this.localization.resolve(shaka.ui.Locales.Ids.FAST_FORWARD));
   }
 
   /**
diff --git a/ui/fullscreen_button.js b/ui/fullscreen_button.js
index 252cad775b..4fe82ddbc3 100644
--- a/ui/fullscreen_button.js
+++ b/ui/fullscreen_button.js
@@ -80,8 +80,7 @@ shaka.ui.FullscreenButton = class extends shaka.ui.Element {
   updateAriaLabel_() {
     const LocIds = shaka.ui.Locales.Ids;
     const label = document.fullscreenElement ?
-                   LocIds.ARIA_LABEL_EXIT_FULL_SCREEN :
-                   LocIds.ARIA_LABEL_FULL_SCREEN;
+        LocIds.EXIT_FULL_SCREEN : LocIds.FULL_SCREEN;
 
     this.button_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
         this.localization.resolve(label));
diff --git a/ui/language_utils.js b/ui/language_utils.js
index efb2cb82bb..09178bfcb6 100644
--- a/ui/language_utils.js
+++ b/ui/language_utils.js
@@ -114,9 +114,11 @@ shaka.ui.LanguageUtils = class {
     // are used to indicate something that isn't one specific language.
     switch (locale) {
       case 'mul':
-        return resolve(shaka.ui.Locales.Ids.LABEL_MULTIPLE_LANGUAGES);
+        return resolve(shaka.ui.Locales.Ids.MULTIPLE_LANGUAGES);
+      case 'und':
+        return resolve(shaka.ui.Locales.Ids.UNDETERMINED_LANGUAGE);
       case 'zxx':
-        return resolve(shaka.ui.Locales.Ids.LABEL_NOT_APPLICABLE);
+        return resolve(shaka.ui.Locales.Ids.NOT_APPLICABLE);
     }
 
     // Extract the base language from the locale as a fallback step.
@@ -134,7 +136,7 @@ shaka.ui.LanguageUtils = class {
       return mozilla.LanguageMapping[language].nativeName +
           ' (' + locale + ')';
     } else {
-      return resolve(shaka.ui.Locales.Ids.LABEL_UNKNOWN_LANGUAGE) +
+      return resolve(shaka.ui.Locales.Ids.UNRECOGNIZED_LANGUAGE) +
           ' (' + locale + ')';
     }
   }
diff --git a/ui/locales.js b/ui/locales.js
deleted file mode 100644
index b7a35b514a..0000000000
--- a/ui/locales.js
+++ /dev/null
@@ -1,683 +0,0 @@
-/**
- * @license
- * Copyright 2016 Google Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-
-// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
-// This file is auto-generated. DO NOT EDIT THIS FILE. If you need to:
-//   - change which locales are in this file, update "build/locales.json"
-//   - change an entry for a specific locale, update "build/locales.json"
-//   - change anything else, update "build/generate-locales.py".
-//
-// To regenerate this file, run "build/generate-locales.py".
-// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
-
-goog.provide('shaka.ui.Locales');
-goog.provide('shaka.ui.Locales.Ids');
-goog.require('shaka.ui.Localization');
-
-/**
- * Insert all localization data for the UI into |localization|. This should be
- * done BEFORE any listeners are added to the localization system (to avoid
- * callbacks for each insert) and should be done BEFORE changing to the initial
- * preferred locale (reduces the work needed to update the internal state after
- * each insert).
- *
- * @param {!shaka.ui.Localization} localization
- */
-
-shaka.ui.Locales.apply = function(localization) {
-  localization.insert('ar', new Map([
-    ['1050953507607739202', 'الحجم'],
-    ['1077325112364709655', 'رجوع'],
-    ['1142734805932039923', 'إرجاع'],
-    ['142853231704504146', 'تشغيل'],
-    ['1774834209035716827', 'تقديم سريع'],
-    ['1911090580951495029', 'الترجمة'],
-    ['2023925063728908356', 'إلغاء كتم الصوت'],
-    ['298626259350585300', 'غير معروفة'],
-    ['3045980486001972586', 'مباشر'],
-    ['3278592358864783064', 'اللغة'],
-    ['4242938254936928940', 'الدخول في وضع "نافذة ضمن نافذة"'],
-    ['4259064532355692191', 'تلقائي'],
-    ['4388316720828367903', 'إعدادات إضافية'],
-    ['5146287486336231188', 'غير سارٍ'],
-    ['5553522235935533682', 'شريط تمرير البحث'],
-    ['5963689277976480680', 'كتم الصوت'],
-    ['6073266792045231479', ''],
-    ['6161306839322897077', 'إنهاء وضع ملء الشاشة'],
-    ['622115170869907732', 'نافذة ضمن النافذة'],
-    ['6614181658619787283', 'الخروج من وضع "نافذة ضمن نافذة"'],
-    ['7071612439610534706', 'إرسال...'],
-    ['8145129506114534451', 'إيقاف'],
-    ['8345190086337560158', 'ملء الشاشة'],
-    ['836055097473758014', 'تشغيل'],
-    ['9042260521669277115', 'إيقاف مؤقت'],
-  ]));
-  localization.insert('de', new Map([
-    ['1050953507607739202', 'Lautstärke'],
-    ['1077325112364709655', 'Zurück'],
-    ['1142734805932039923', 'Zurückspulen'],
-    ['142853231704504146', 'An'],
-    ['1774834209035716827', 'Vorspulen'],
-    ['1911090580951495029', 'Untertitel'],
-    ['2023925063728908356', 'Stummschaltung aufheben'],
-    ['298626259350585300', 'Unbekannt'],
-    ['3045980486001972586', 'Live'],
-    ['3278592358864783064', 'Sprache'],
-    ['4242938254936928940', 'Bild-im-Bild-Modus aktivieren'],
-    ['4259064532355692191', 'Automatisch'],
-    ['4388316720828367903', 'Weitere Einstellungen'],
-    ['5146287486336231188', 'Nicht zutreffend'],
-    ['5553522235935533682', 'Schieberegler für Suche'],
-    ['5963689277976480680', 'Stummschalten'],
-    ['6073266792045231479', 'Auflösung'],
-    ['6161306839322897077', 'Vollbildmodus beenden'],
-    ['622115170869907732', 'Bild-in-Bild'],
-    ['6614181658619787283', 'Bild-im-Bild-Modus beenden'],
-    ['7071612439610534706', 'Streamen…'],
-    ['8145129506114534451', 'Aus'],
-    ['8345190086337560158', 'Vollbild'],
-    ['836055097473758014', 'Wiedergeben'],
-    ['9042260521669277115', 'Pausieren'],
-  ]));
-  localization.insert('en', new Map([
-    ['1050953507607739202', 'volume'],
-    ['1077325112364709655', 'Back'],
-    ['1142734805932039923', 'Rewind'],
-    ['142853231704504146', 'on'],
-    ['1774834209035716827', 'Fast-forward'],
-    ['1911090580951495029', 'Captions'],
-    ['2023925063728908356', 'Unmute'],
-    ['298626259350585300', 'Unknown'],
-    ['3045980486001972586', 'Live'],
-    ['3278592358864783064', 'Language'],
-    ['4242938254936928940', 'enter picture-in-picture'],
-    ['4259064532355692191', 'Auto'],
-    ['4388316720828367903', 'More settings'],
-    ['5146287486336231188', 'Not applicable'],
-    ['5553522235935533682', 'Seek slider'],
-    ['5963689277976480680', 'Mute'],
-    ['6073266792045231479', 'Resolution'],
-    ['6161306839322897077', 'Exit full screen'],
-    ['622115170869907732', 'Picture in Picture'],
-    ['6614181658619787283', 'exit picture-in-picture'],
-    ['7071612439610534706', 'Cast...'],
-    ['8145129506114534451', 'Off'],
-    ['8345190086337560158', 'Full screen'],
-    ['836055097473758014', 'Play'],
-    ['9042260521669277115', 'Pause'],
-  ]));
-  localization.insert('en-GB', new Map([
-    ['1050953507607739202', 'volume'],
-    ['1077325112364709655', 'Back'],
-    ['1142734805932039923', 'Rewind'],
-    ['142853231704504146', 'on'],
-    ['1774834209035716827', 'Fast-forward'],
-    ['1911090580951495029', 'Captions'],
-    ['2023925063728908356', 'Unmute'],
-    ['298626259350585300', 'Unknown'],
-    ['3045980486001972586', 'Live'],
-    ['3278592358864783064', 'Language'],
-    ['4242938254936928940', 'enter picture-in-picture'],
-    ['4259064532355692191', 'Auto'],
-    ['4388316720828367903', 'More settings'],
-    ['5146287486336231188', 'Not applicable'],
-    ['5553522235935533682', 'Seek slider'],
-    ['5963689277976480680', 'Mute'],
-    ['6073266792045231479', 'Resolution'],
-    ['6161306839322897077', 'Exit full screen'],
-    ['622115170869907732', 'Picture in Picture'],
-    ['6614181658619787283', 'exit picture-in-picture'],
-    ['7071612439610534706', 'Cast...'],
-    ['8145129506114534451', 'Off'],
-    ['8345190086337560158', 'Full screen'],
-    ['836055097473758014', 'Play'],
-    ['9042260521669277115', 'Pause'],
-  ]));
-  localization.insert('es', new Map([
-    ['1050953507607739202', 'volumen'],
-    ['1077325112364709655', 'Atrás'],
-    ['1142734805932039923', 'Retroceder'],
-    ['142853231704504146', 'activado'],
-    ['1774834209035716827', 'Avance rápido'],
-    ['1911090580951495029', 'Subtítulos'],
-    ['2023925063728908356', 'Activar sonido'],
-    ['298626259350585300', 'Desconocido'],
-    ['3045980486001972586', 'En directo'],
-    ['3278592358864783064', 'Idioma'],
-    ['4242938254936928940', 'abrir el modo imagen en imagen'],
-    ['4259064532355692191', 'Automática'],
-    ['4388316720828367903', 'Más ajustes'],
-    ['5146287486336231188', 'No aplicable'],
-    ['5553522235935533682', 'Barra deslizante de búsqueda'],
-    ['5963689277976480680', 'Silenciar'],
-    ['6073266792045231479', 'Resolución'],
-    ['6161306839322897077', 'Salir del modo de pantalla completa'],
-    ['622115170869907732', 'Imagen en imagen'],
-    ['6614181658619787283', 'salir del modo imagen en imagen'],
-    ['7071612439610534706', 'Reparto...'],
-    ['8145129506114534451', 'No'],
-    ['8345190086337560158', 'Pantalla completa'],
-    ['836055097473758014', 'Reproducir'],
-    ['9042260521669277115', 'Pausa'],
-  ]));
-  localization.insert('es-419', new Map([
-    ['1050953507607739202', 'volumen'],
-    ['1077325112364709655', 'Atrás'],
-    ['1142734805932039923', 'Retroceder'],
-    ['142853231704504146', 'activado'],
-    ['1774834209035716827', 'Avance rápido'],
-    ['1911090580951495029', 'Subtítulos'],
-    ['2023925063728908356', 'Activar sonido'],
-    ['298626259350585300', 'Desconocido'],
-    ['3045980486001972586', 'En vivo'],
-    ['3278592358864783064', 'Idioma'],
-    ['4242938254936928940', 'ingresar al modo de pantalla en pantalla'],
-    ['4259064532355692191', 'Auto'],
-    ['4388316720828367903', 'Más opciones de configuración'],
-    ['5146287486336231188', 'No aplicable'],
-    ['5553522235935533682', 'Barra deslizante de búsqueda'],
-    ['5963689277976480680', 'Silenciar'],
-    ['6073266792045231479', 'Resolución'],
-    ['6161306839322897077', 'Salir de pantalla completa'],
-    ['622115170869907732', 'Pantalla en pantalla'],
-    ['6614181658619787283', 'salir del modo de pantalla en pantalla'],
-    ['7071612439610534706', 'Transmitir…'],
-    ['8145129506114534451', 'Desactivado'],
-    ['8345190086337560158', 'Pantalla completa'],
-    ['836055097473758014', 'Jugar'],
-    ['9042260521669277115', 'Detener'],
-  ]));
-  localization.insert('fr', new Map([
-    ['1050953507607739202', 'volume'],
-    ['1077325112364709655', 'Retour'],
-    ['1142734805932039923', 'Retour arrière'],
-    ['142853231704504146', 'activé'],
-    ['1774834209035716827', 'Avance rapide'],
-    ['1911090580951495029', 'Sous-titres'],
-    ['2023925063728908356', 'Activer le son'],
-    ['298626259350585300', 'Inconnue'],
-    ['3045980486001972586', 'En direct'],
-    ['3278592358864783064', 'Langue'],
-    ['4242938254936928940', 'utiliser le mode PIP'],
-    ['4259064532355692191', 'Auto'],
-    ['4388316720828367903', 'Autres paramètres'],
-    ['5146287486336231188', 'Non applicable'],
-    ['5553522235935533682', 'Barre de recherche'],
-    ['5963689277976480680', 'Désactiver le son'],
-    ['6073266792045231479', 'Résolution'],
-    ['6161306839322897077', 'Quitter le mode plein écran'],
-    ['622115170869907732', 'Picture-in-picture'],
-    ['6614181658619787283', 'quitter le mode PIP'],
-    ['7071612439610534706', 'Caster sur…'],
-    ['8145129506114534451', 'Désactivée'],
-    ['8345190086337560158', 'Plein écran'],
-    ['836055097473758014', 'Lire'],
-    ['9042260521669277115', 'Mettre en veille'],
-  ]));
-  localization.insert('it', new Map([
-    ['1050953507607739202', 'volume'],
-    ['1077325112364709655', 'Indietro'],
-    ['1142734805932039923', 'Riavvolgi'],
-    ['142853231704504146', 'on'],
-    ['1774834209035716827', 'Avanti veloce'],
-    ['1911090580951495029', 'Sottotitoli'],
-    ['2023925063728908356', 'Riattiva audio'],
-    ['298626259350585300', 'Sconosciuto'],
-    ['3045980486001972586', 'Dal vivo'],
-    ['3278592358864783064', 'Lingua'],
-    ['4242938254936928940', 'attiva picture in picture'],
-    ['4259064532355692191', 'Auto'],
-    ['4388316720828367903', 'Altre impostazioni'],
-    ['5146287486336231188', 'Non applicable'],
-    ['5553522235935533682', 'Dispositivo di scorrimento'],
-    ['5963689277976480680', 'Disattiva audio'],
-    ['6073266792045231479', 'Risoluzione'],
-    ['6161306839322897077', 'Esci dalla modalità a schermo intero'],
-    ['622115170869907732', 'Picture in picture'],
-    ['6614181658619787283', 'esci da picture in picture'],
-    ['7071612439610534706', 'Trasmetti…'],
-    ['8145129506114534451', 'Disattivato'],
-    ['8345190086337560158', 'Schermo intero'],
-    ['836055097473758014', 'Riproduci'],
-    ['9042260521669277115', 'Metti in pausa'],
-  ]));
-  localization.insert('ja', new Map([
-    ['1050953507607739202', '音量'],
-    ['1077325112364709655', '戻る'],
-    ['1142734805932039923', '巻き戻し'],
-    ['142853231704504146', 'オン'],
-    ['1774834209035716827', '早送り'],
-    ['1911090580951495029', '字幕'],
-    ['2023925063728908356', 'ミュート解除'],
-    ['298626259350585300', '不明'],
-    ['3045980486001972586', 'ライブ'],
-    ['3278592358864783064', '言語'],
-    ['4242938254936928940', 'ピクチャー イン ピクチャーを開始します'],
-    ['4259064532355692191', '自動'],
-    ['4388316720828367903', 'その他の設定'],
-    ['5146287486336231188', '--'],
-    ['5553522235935533682', 'シーク バー'],
-    ['5963689277976480680', 'ミュート'],
-    ['6073266792045231479', '解像度'],
-    ['6161306839322897077', '全画面モードの終了'],
-    ['622115170869907732', 'ピクチャー イン ピクチャー'],
-    ['6614181658619787283', 'ピクチャー イン ピクチャーを終了します'],
-    ['7071612439610534706', 'キャスト...'],
-    ['8145129506114534451', 'オフ'],
-    ['8345190086337560158', '全画面'],
-    ['836055097473758014', '再生'],
-    ['9042260521669277115', '一時停止'],
-  ]));
-  localization.insert('ko', new Map([
-    ['1050953507607739202', '볼륨'],
-    ['1077325112364709655', '뒤로'],
-    ['1142734805932039923', '되감기'],
-    ['142853231704504146', '사용'],
-    ['1774834209035716827', '빨리감기'],
-    ['1911090580951495029', '자막'],
-    ['2023925063728908356', '음소거 해제'],
-    ['298626259350585300', '알 수 없음'],
-    ['3045980486001972586', '라이브'],
-    ['3278592358864783064', '언어'],
-    ['4242938254936928940', 'PIP 모드 시작'],
-    ['4259064532355692191', '자동'],
-    ['4388316720828367903', '설정 더보기'],
-    ['5146287486336231188', '해당 사항 없음'],
-    ['5553522235935533682', '탐색 슬라이더'],
-    ['5963689277976480680', '음소거'],
-    ['6073266792045231479', '해상도'],
-    ['6161306839322897077', '전체화면 종료'],
-    ['622115170869907732', 'PIP 모드'],
-    ['6614181658619787283', 'PIP 모드 종료'],
-    ['7071612439610534706', '전송...'],
-    ['8145129506114534451', '사용 안함'],
-    ['8345190086337560158', '전체화면'],
-    ['836055097473758014', '재생'],
-    ['9042260521669277115', '일시중지'],
-  ]));
-  localization.insert('nl', new Map([
-    ['1050953507607739202', 'volume'],
-    ['1077325112364709655', 'Terug'],
-    ['1142734805932039923', 'Terugspoelen'],
-    ['142853231704504146', 'aan'],
-    ['1774834209035716827', 'Vooruitspoelen'],
-    ['1911090580951495029', 'Ondertiteling'],
-    ['2023925063728908356', 'Dempen opheffen'],
-    ['298626259350585300', 'Onbekend'],
-    ['3045980486001972586', 'Live'],
-    ['3278592358864783064', 'Taal'],
-    ['4242938254936928940', 'scherm-in-scherm openen'],
-    ['4259064532355692191', 'Automatisch'],
-    ['4388316720828367903', 'Meer instellingen'],
-    ['5146287486336231188', 'Niet van toepassing'],
-    ['5553522235935533682', 'Zoekschuifbalk'],
-    ['5963689277976480680', 'Dempen'],
-    ['6073266792045231479', 'Resolutie'],
-    ['6161306839322897077', 'Volledig scherm afsluiten'],
-    ['622115170869907732', 'Scherm-in-scherm'],
-    ['6614181658619787283', 'scherm-in-scherm afsluiten'],
-    ['7071612439610534706', 'Casten...'],
-    ['8145129506114534451', 'Uit'],
-    ['8345190086337560158', 'Volledig scherm'],
-    ['836055097473758014', 'Afspelen'],
-    ['9042260521669277115', 'Onderbreken'],
-  ]));
-  localization.insert('pl', new Map([
-    ['1050953507607739202', 'głośność'],
-    ['1077325112364709655', 'Wstecz'],
-    ['1142734805932039923', 'Przewiń do tyłu'],
-    ['142853231704504146', 'wł.'],
-    ['1774834209035716827', 'Przewiń do przodu'],
-    ['1911090580951495029', 'Napisy'],
-    ['2023925063728908356', 'Wyłącz wyciszenie'],
-    ['298626259350585300', 'Nieznane'],
-    ['3045980486001972586', 'Na żywo'],
-    ['3278592358864783064', 'Język'],
-    ['4242938254936928940', 'włącz tryb obrazu w obrazie'],
-    ['4259064532355692191', 'Automatyczna'],
-    ['4388316720828367903', 'Więcej ustawień'],
-    ['5146287486336231188', 'Nie dotyczy'],
-    ['5553522235935533682', 'Suwak przewijania'],
-    ['5963689277976480680', 'Wycisz'],
-    ['6073266792045231479', 'Rozdzielczość'],
-    ['6161306839322897077', 'Zamknij pełny ekran'],
-    ['622115170869907732', 'Obraz w obrazie'],
-    ['6614181658619787283', 'wyłącz tryb obrazu w obrazie'],
-    ['7071612439610534706', 'Prześlij...'],
-    ['8145129506114534451', 'Wyłączone'],
-    ['8345190086337560158', 'Pełny ekran'],
-    ['836055097473758014', 'Odtwarzaj'],
-    ['9042260521669277115', 'Wstrzymaj'],
-  ]));
-  localization.insert('pt-BR', new Map([
-    ['1050953507607739202', 'volume'],
-    ['1077325112364709655', 'Voltar'],
-    ['1142734805932039923', 'Retroceder'],
-    ['142853231704504146', 'ativado'],
-    ['1774834209035716827', 'Avançar'],
-    ['1911090580951495029', 'Legendas ocultas'],
-    ['2023925063728908356', 'Ativar som'],
-    ['298626259350585300', 'Desconhecido'],
-    ['3045980486001972586', 'Ao vivo'],
-    ['3278592358864783064', 'Idioma'],
-    ['4242938254936928940', 'entrar no modo picture-in-picture'],
-    ['4259064532355692191', 'Automático'],
-    ['4388316720828367903', 'Mais configurações'],
-    ['5146287486336231188', 'Não aplicável'],
-    ['5553522235935533682', 'Botão deslizante de busca'],
-    ['5963689277976480680', 'Desativar som'],
-    ['6073266792045231479', 'Resolução'],
-    ['6161306839322897077', 'Sair da tela inteira'],
-    ['622115170869907732', 'Picture-in-picture'],
-    ['6614181658619787283', 'sair de picture-in-picture'],
-    ['7071612439610534706', 'Elenco...'],
-    ['8145129506114534451', 'Desativado'],
-    ['8345190086337560158', 'Tela inteira'],
-    ['836055097473758014', 'Reproduzir'],
-    ['9042260521669277115', 'Pausar'],
-  ]));
-  localization.insert('pt-PT', new Map([
-    ['1050953507607739202', 'volume'],
-    ['1077325112364709655', 'Anterior'],
-    ['1142734805932039923', 'Recuar'],
-    ['142853231704504146', 'ativado'],
-    ['1774834209035716827', 'Avançar'],
-    ['1911090580951495029', 'Legendas'],
-    ['2023925063728908356', 'Reativar o som'],
-    ['298626259350585300', 'Desconhecida'],
-    ['3045980486001972586', 'Em direto'],
-    ['3278592358864783064', 'Idioma'],
-    ['4242938254936928940', 'entrar no modo ecrã no ecrã'],
-    ['4259064532355692191', 'Automático'],
-    ['4388316720828367903', 'Mais definições'],
-    ['5146287486336231188', 'Não aplicável'],
-    ['5553522235935533682', 'Controlo de deslize da procura'],
-    ['5963689277976480680', 'Desativar o som'],
-    ['6073266792045231479', 'Resolução'],
-    ['6161306839322897077', 'Sair do ecrã inteiro'],
-    ['622115170869907732', 'Ecrã no ecrã'],
-    ['6614181658619787283', 'sair do modo ecrã no ecrã'],
-    ['7071612439610534706', 'Transmitir...'],
-    ['8145129506114534451', 'Desativado'],
-    ['8345190086337560158', 'Ecrã inteiro'],
-    ['836055097473758014', 'Reproduzir'],
-    ['9042260521669277115', 'Colocar em pausa'],
-  ]));
-  localization.insert('ru', new Map([
-    ['1050953507607739202', 'громкость'],
-    ['1077325112364709655', 'Назад'],
-    ['1142734805932039923', 'Перемотать назад'],
-    ['142853231704504146', 'ВКЛ'],
-    ['1774834209035716827', 'Перемотать вперед'],
-    ['1911090580951495029', 'Субтитры'],
-    ['2023925063728908356', 'Включить звук'],
-    ['298626259350585300', 'Неизвестно'],
-    ['3045980486001972586', 'В эфире'],
-    ['3278592358864783064', 'Язык'],
-    ['4242938254936928940', 'включить режим "Картинка в картинке"'],
-    ['4259064532355692191', 'Автонастройка'],
-    ['4388316720828367903', 'Дополнительные настройки'],
-    ['5146287486336231188', 'Неприменимо'],
-    ['5553522235935533682', 'Ползунок поиска'],
-    ['5963689277976480680', 'Отключить звук'],
-    ['6073266792045231479', 'Разрешение'],
-    ['6161306839322897077', 'Выход из полноэкранного режима'],
-    ['622115170869907732', 'Картинка в картинке'],
-    ['6614181658619787283', 'выйти из режима "Картинка в картинке"'],
-    ['7071612439610534706', 'Хромкаст'],
-    ['8145129506114534451', 'Выкл.'],
-    ['8345190086337560158', 'Во весь экран'],
-    ['836055097473758014', 'Смотреть'],
-    ['9042260521669277115', 'Приостановить'],
-  ]));
-  localization.insert('th', new Map([
-    ['1050953507607739202', 'ระดับเสียง'],
-    ['1077325112364709655', 'กลับ'],
-    ['1142734805932039923', 'กรอกลับ'],
-    ['142853231704504146', 'เปิด'],
-    ['1774834209035716827', 'กรอไปข้างหน้า'],
-    ['1911090580951495029', 'คำอธิบายวิดีโอ'],
-    ['2023925063728908356', 'เปิดเสียง'],
-    ['298626259350585300', 'ไม่ทราบ'],
-    ['3045980486001972586', 'สด'],
-    ['3278592358864783064', 'ภาษา'],
-    ['4242938254936928940', 'เข้าสู่การแสดงภาพซ้อนภาพ'],
-    ['4259064532355692191', 'อัตโนมัติ'],
-    ['4388316720828367903', 'การตั้งค่าเพิ่มเติม'],
-    ['5146287486336231188', 'ไม่เกี่ยวข้อง'],
-    ['5553522235935533682', 'แถบเลื่อนค้นหา'],
-    ['5963689277976480680', 'ปิดเสียง'],
-    ['6073266792045231479', 'ความละเอียด'],
-    ['6161306839322897077', 'ออกจากโหมดเต็มหน้าจอ'],
-    ['622115170869907732', 'การแสดงภาพซ้อนภาพ'],
-    ['6614181658619787283', 'ออกจากการแสดงภาพซ้อนภาพ'],
-    ['7071612439610534706', 'แคสต์...'],
-    ['8145129506114534451', 'ปิด'],
-    ['8345190086337560158', 'เต็มหน้าจอ'],
-    ['836055097473758014', 'เล่น'],
-    ['9042260521669277115', 'หยุดชั่วคราว'],
-  ]));
-  localization.insert('tr', new Map([
-    ['1050953507607739202', 'ses düzeyi'],
-    ['1077325112364709655', 'Geri'],
-    ['1142734805932039923', 'Geri sar'],
-    ['142853231704504146', 'açık'],
-    ['1774834209035716827', 'İleri sar'],
-    ['1911090580951495029', 'Altyazılar'],
-    ['2023925063728908356', 'Sesi aç'],
-    ['298626259350585300', 'Bilinmiyor'],
-    ['3045980486001972586', 'Canlı'],
-    ['3278592358864783064', 'Dil'],
-    ['4242938254936928940', 'pencere içinde pencere moduna gir'],
-    ['4259064532355692191', 'Otomatik'],
-    ['4388316720828367903', 'Diğer ayarlar'],
-    ['5146287486336231188', 'Kullanılmıyor'],
-    ['5553522235935533682', 'Arama kaydırma çubuğu'],
-    ['5963689277976480680', 'Sesi kapat'],
-    ['6073266792045231479', 'Çözünürlük'],
-    ['6161306839322897077', 'Tam ekrandan çık'],
-    ['622115170869907732', 'Pencere içinde Pencere'],
-    ['6614181658619787283', 'pencere içinde pencere modundan çıkın'],
-    ['7071612439610534706', 'Yayınla...'],
-    ['8145129506114534451', 'Kapalı'],
-    ['8345190086337560158', 'Tam ekran'],
-    ['836055097473758014', 'Oynat'],
-    ['9042260521669277115', 'Duraklat'],
-  ]));
-  localization.insert('zh-CN', new Map([
-    ['1050953507607739202', '音量'],
-    ['1077325112364709655', '返回'],
-    ['1142734805932039923', '快退'],
-    ['142853231704504146', '开启'],
-    ['1774834209035716827', '快进'],
-    ['1911090580951495029', '字幕'],
-    ['2023925063728908356', '取消静音'],
-    ['298626259350585300', '未知'],
-    ['3045980486001972586', '直播'],
-    ['3278592358864783064', '语言'],
-    ['4242938254936928940', '进入“画中画”模式'],
-    ['4259064532355692191', '自动'],
-    ['4388316720828367903', '更多设置'],
-    ['5146287486336231188', '不適用'],
-    ['5553522235935533682', '播放滑块'],
-    ['5963689277976480680', '静音'],
-    ['6073266792045231479', '分辨率'],
-    ['6161306839322897077', '退出全屏'],
-    ['622115170869907732', '画中画'],
-    ['6614181658619787283', '退出“画中画”模式'],
-    ['7071612439610534706', '投射…'],
-    ['8145129506114534451', '关闭'],
-    ['8345190086337560158', '全屏'],
-    ['836055097473758014', '播放'],
-    ['9042260521669277115', '暂停'],
-  ]));
-  localization.insert('zh-HK', new Map([
-    ['1050953507607739202', '音量'],
-    ['1077325112364709655', '返回'],
-    ['1142734805932039923', '倒帶'],
-    ['142853231704504146', ''],
-    ['1774834209035716827', '快轉'],
-    ['1911090580951495029', '字幕'],
-    ['2023925063728908356', '解除靜音'],
-    ['298626259350585300', '不明'],
-    ['3045980486001972586', '直播'],
-    ['3278592358864783064', '語言'],
-    ['4242938254936928940', '進入畫中畫'],
-    ['4259064532355692191', '自動'],
-    ['4388316720828367903', '更多設定'],
-    ['5146287486336231188', '不適用'],
-    ['5553522235935533682', '搜尋滑桿'],
-    ['5963689277976480680', '靜音'],
-    ['6073266792045231479', ''],
-    ['6161306839322897077', '結束全螢幕'],
-    ['622115170869907732', '畫中畫'],
-    ['6614181658619787283', '退出畫中畫'],
-    ['7071612439610534706', '投放…'],
-    ['8145129506114534451', '未選取'],
-    ['8345190086337560158', '全螢幕'],
-    ['836055097473758014', '播放'],
-    ['9042260521669277115', '暫停'],
-  ]));
-  localization.insert('zh-TW', new Map([
-    ['1050953507607739202', '音量'],
-    ['1077325112364709655', '返回'],
-    ['1142734805932039923', '倒轉'],
-    ['142853231704504146', '開啟'],
-    ['1774834209035716827', '快轉'],
-    ['1911090580951495029', '字幕'],
-    ['2023925063728908356', '解除靜音'],
-    ['298626259350585300', '未知'],
-    ['3045980486001972586', '直播'],
-    ['3278592358864783064', '語言'],
-    ['4242938254936928940', '進入子母畫面'],
-    ['4259064532355692191', '自動'],
-    ['4388316720828367903', '更多設定'],
-    ['5146287486336231188', '不適用'],
-    ['5553522235935533682', '搜尋滑桿'],
-    ['5963689277976480680', '靜音'],
-    ['6073266792045231479', '解析度'],
-    ['6161306839322897077', '結束全螢幕'],
-    ['622115170869907732', '子母畫面'],
-    ['6614181658619787283', '離開子母畫面'],
-    ['7071612439610534706', '投放…'],
-    ['8145129506114534451', '關閉'],
-    ['8345190086337560158', '全螢幕'],
-    ['836055097473758014', '播放'],
-    ['9042260521669277115', '暫停'],
-  ]));
-};
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_BACK = '1077325112364709655';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_CAPTIONS = '1911090580951495029';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_CAST = '7071612439610534706';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_ENTER_PICTURE_IN_PICTURE =
-    '4242938254936928940';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_EXIT_FULL_SCREEN = '6161306839322897077';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_EXIT_PICTURE_IN_PICTURE = '6614181658619787283';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_FAST_FORWARD = '1774834209035716827';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_FULL_SCREEN = '8345190086337560158';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_LANGUAGE = '3278592358864783064';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_LIVE = '3045980486001972586';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_MORE_SETTINGS = '4388316720828367903';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_MUTE = '5963689277976480680';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_PAUSE = '9042260521669277115';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_PLAY = '836055097473758014';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_RESOLUTION = '6073266792045231479';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_REWIND = '1142734805932039923';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_SEEK = '5553522235935533682';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_UNMUTE = '2023925063728908356';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.ARIA_LABEL_VOLUME = '1050953507607739202';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.LABEL_AUTO_QUALITY = '4259064532355692191';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.LABEL_CAPTIONS = '1911090580951495029';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.LABEL_CAPTIONS_OFF = '8145129506114534451';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.LABEL_CAST = '7071612439610534706';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.LABEL_LANGUAGE = '3278592358864783064';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.LABEL_LIVE = '3045980486001972586';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.LABEL_MULTIPLE_LANGUAGES = '411375375680850814';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.LABEL_NOT_APPLICABLE = '5146287486336231188';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.LABEL_NOT_CASTING = '8145129506114534451';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.LABEL_PICTURE_IN_PICTURE = '622115170869907732';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.LABEL_PICTURE_IN_PICTURE_OFF = '8145129506114534451';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.LABEL_PICTURE_IN_PICTURE_ON = '142853231704504146';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.LABEL_RESOLUTION = '6073266792045231479';
-
-/** @const {string} */
-shaka.ui.Locales.Ids.LABEL_UNKNOWN_LANGUAGE = '298626259350585300';
diff --git a/ui/locales/ar.json b/ui/locales/ar.json
new file mode 100644
index 0000000000..fe34541ae6
--- /dev/null
+++ b/ui/locales/ar.json
@@ -0,0 +1,29 @@
+{
+  "FULL_SCREEN": "ملء الشاشة",
+  "EXIT_FULL_SCREEN": "إنهاء وضع ملء الشاشة",
+  "FAST_FORWARD": "تقديم سريع",
+  "REWIND": "إرجاع",
+  "MUTE": "كتم الصوت",
+  "UNMUTE": "إلغاء كتم الصوت",
+  "PAUSE": "إيقاف مؤقت",
+  "PLAY": "تشغيل",
+  "SEEK": "شريط تمرير البحث",
+  "VOLUME": "الحجم",
+  "SKIP_TO_LIVE": "مباشر",
+  "LIVE": "مباشر",
+  "MORE_SETTINGS": "إعدادات إضافية",
+  "BACK": "رجوع",
+  "CAPTIONS": "الترجمة",
+  "RESOLUTION": "",
+  "AUTO_QUALITY": "تلقائي",
+  "CAST": "إرسال...",
+  "LANGUAGE": "اللغة",
+  "UNRECOGNIZED_LANGUAGE": "غير معروفة",
+  "UNDETERMINED_LANGUAGE": "غير معروفة",
+  "NOT_APPLICABLE": "غير سارٍ",
+  "ENTER_PICTURE_IN_PICTURE": "الدخول في وضع \"نافذة ضمن نافذة\"",
+  "EXIT_PICTURE_IN_PICTURE": "الخروج من وضع \"نافذة ضمن نافذة\"",
+  "PICTURE_IN_PICTURE": "نافذة ضمن النافذة",
+  "ON": "تشغيل",
+  "OFF": "إيقاف"
+}
diff --git a/ui/locales/de.json b/ui/locales/de.json
new file mode 100644
index 0000000000..f564057ca5
--- /dev/null
+++ b/ui/locales/de.json
@@ -0,0 +1,30 @@
+{
+  "FULL_SCREEN": "Vollbild",
+  "EXIT_FULL_SCREEN": "Vollbildmodus beenden",
+  "FAST_FORWARD": "Vorspulen",
+  "REWIND": "Zurückspulen",
+  "MUTE": "Stummschalten",
+  "UNMUTE": "Stummschaltung aufheben",
+  "PAUSE": "Pausieren",
+  "PLAY": "Wiedergeben",
+  "SEEK": "Schieberegler für Suche",
+  "VOLUME": "Lautstärke",
+  "SKIP_TO_LIVE": "Live",
+  "LIVE": "Live",
+  "MORE_SETTINGS": "Weitere Einstellungen",
+  "BACK": "Zurück",
+  "CAPTIONS": "Untertitel",
+  "RESOLUTION": "Auflösung",
+  "AUTO_QUALITY": "Automatisch",
+  "CAST": "Streamen…",
+  "LANGUAGE": "Sprache",
+  "UNRECOGNIZED_LANGUAGE": "Unerkannt",
+  "UNDETERMINED_LANGUAGE": "Unbestimmt",
+  "MULTIPLE_LANGUAGES": "mehrere Sprachen",
+  "NOT_APPLICABLE": "Nicht zutreffend",
+  "ENTER_PICTURE_IN_PICTURE": "Bild-im-Bild-Modus aktivieren",
+  "EXIT_PICTURE_IN_PICTURE": "Bild-im-Bild-Modus beenden",
+  "PICTURE_IN_PICTURE": "Bild-in-Bild",
+  "ON": "An",
+  "OFF": "Aus"
+}
diff --git a/ui/locales/en-GB.json b/ui/locales/en-GB.json
new file mode 100644
index 0000000000..d6f5ec0bdd
--- /dev/null
+++ b/ui/locales/en-GB.json
@@ -0,0 +1,30 @@
+{
+  "FULL_SCREEN": "Full screen",
+  "EXIT_FULL_SCREEN": "Exit full screen",
+  "FAST_FORWARD": "Fast-forward",
+  "REWIND": "Rewind",
+  "MUTE": "Mute",
+  "UNMUTE": "Unmute",
+  "PAUSE": "Pause",
+  "PLAY": "Play",
+  "SEEK": "Seek",
+  "VOLUME": "Volume",
+  "SKIP_TO_LIVE": "Skip ahead to live",
+  "LIVE": "Live",
+  "MORE_SETTINGS": "More settings",
+  "BACK": "Back",
+  "CAPTIONS": "Captions",
+  "RESOLUTION": "Resolution",
+  "AUTO_QUALITY": "Auto",
+  "CAST": "Cast...",
+  "LANGUAGE": "Language",
+  "UNRECOGNIZED_LANGUAGE": "Unrecognized",
+  "UNDETERMINED_LANGUAGE": "Undetermined",
+  "MULTIPLE_LANGUAGES": "Multiple languages",
+  "NOT_APPLICABLE": "Not applicable",
+  "ENTER_PICTURE_IN_PICTURE": "Enter Picture-in-Picture",
+  "EXIT_PICTURE_IN_PICTURE": "Exit Picture-in-Picture",
+  "PICTURE_IN_PICTURE": "Picture-in-Picture",
+  "ON": "On",
+  "OFF": "Off"
+}
diff --git a/ui/locales/en.json b/ui/locales/en.json
new file mode 100644
index 0000000000..d6f5ec0bdd
--- /dev/null
+++ b/ui/locales/en.json
@@ -0,0 +1,30 @@
+{
+  "FULL_SCREEN": "Full screen",
+  "EXIT_FULL_SCREEN": "Exit full screen",
+  "FAST_FORWARD": "Fast-forward",
+  "REWIND": "Rewind",
+  "MUTE": "Mute",
+  "UNMUTE": "Unmute",
+  "PAUSE": "Pause",
+  "PLAY": "Play",
+  "SEEK": "Seek",
+  "VOLUME": "Volume",
+  "SKIP_TO_LIVE": "Skip ahead to live",
+  "LIVE": "Live",
+  "MORE_SETTINGS": "More settings",
+  "BACK": "Back",
+  "CAPTIONS": "Captions",
+  "RESOLUTION": "Resolution",
+  "AUTO_QUALITY": "Auto",
+  "CAST": "Cast...",
+  "LANGUAGE": "Language",
+  "UNRECOGNIZED_LANGUAGE": "Unrecognized",
+  "UNDETERMINED_LANGUAGE": "Undetermined",
+  "MULTIPLE_LANGUAGES": "Multiple languages",
+  "NOT_APPLICABLE": "Not applicable",
+  "ENTER_PICTURE_IN_PICTURE": "Enter Picture-in-Picture",
+  "EXIT_PICTURE_IN_PICTURE": "Exit Picture-in-Picture",
+  "PICTURE_IN_PICTURE": "Picture-in-Picture",
+  "ON": "On",
+  "OFF": "Off"
+}
diff --git a/ui/locales/es-419.json b/ui/locales/es-419.json
new file mode 100644
index 0000000000..2928957092
--- /dev/null
+++ b/ui/locales/es-419.json
@@ -0,0 +1,29 @@
+{
+  "FULL_SCREEN": "Pantalla completa",
+  "EXIT_FULL_SCREEN": "Salir de pantalla completa",
+  "FAST_FORWARD": "Avance rápido",
+  "REWIND": "Retroceder",
+  "MUTE": "Silenciar",
+  "UNMUTE": "Activar sonido",
+  "PAUSE": "Detener",
+  "PLAY": "Jugar",
+  "SEEK": "Barra deslizante de búsqueda",
+  "VOLUME": "volumen",
+  "SKIP_TO_LIVE": "En vivo",
+  "LIVE": "En vivo",
+  "MORE_SETTINGS": "Más opciones de configuración",
+  "BACK": "Atrás",
+  "CAPTIONS": "Subtítulos",
+  "RESOLUTION": "Resolución",
+  "AUTO_QUALITY": "Auto",
+  "CAST": "Transmitir…",
+  "LANGUAGE": "Idioma",
+  "UNRECOGNIZED_LANGUAGE": "Desconocido",
+  "UNDETERMINED_LANGUAGE": "Desconocido",
+  "NOT_APPLICABLE": "No aplicable",
+  "ENTER_PICTURE_IN_PICTURE": "ingresar al modo de pantalla en pantalla",
+  "EXIT_PICTURE_IN_PICTURE": "salir del modo de pantalla en pantalla",
+  "PICTURE_IN_PICTURE": "Pantalla en pantalla",
+  "ON": "activado",
+  "OFF": "Desactivado"
+}
diff --git a/ui/locales/es.json b/ui/locales/es.json
new file mode 100644
index 0000000000..83afebbcb2
--- /dev/null
+++ b/ui/locales/es.json
@@ -0,0 +1,30 @@
+{
+  "FULL_SCREEN": "Pantalla completa",
+  "EXIT_FULL_SCREEN": "Salir del modo de pantalla completa",
+  "FAST_FORWARD": "Avance rápido",
+  "REWIND": "Retroceder",
+  "MUTE": "Silenciar",
+  "UNMUTE": "Activar sonido",
+  "PAUSE": "Pausa",
+  "PLAY": "Reproducir",
+  "SEEK": "Barra deslizante de búsqueda",
+  "VOLUME": "volumen",
+  "SKIP_TO_LIVE": "En directo",
+  "LIVE": "En directo",
+  "MORE_SETTINGS": "Más ajustes",
+  "BACK": "Atrás",
+  "CAPTIONS": "Subtítulos",
+  "RESOLUTION": "Resolución",
+  "AUTO_QUALITY": "Automática",
+  "CAST": "Reparto...",
+  "LANGUAGE": "Idioma",
+  "UNRECOGNIZED_LANGUAGE": "Desconocido",
+  "UNDETERMINED_LANGUAGE": "Desconocido",
+  "MULTIPLE_LANGUAGES": "varios idiomas",
+  "NOT_APPLICABLE": "No aplicable",
+  "ENTER_PICTURE_IN_PICTURE": "abrir el modo imagen en imagen",
+  "EXIT_PICTURE_IN_PICTURE": "salir del modo imagen en imagen",
+  "PICTURE_IN_PICTURE": "Imagen en imagen",
+  "ON": "activado",
+  "OFF": "No"
+}
diff --git a/ui/locales/fr.json b/ui/locales/fr.json
new file mode 100644
index 0000000000..a7c06a55a8
--- /dev/null
+++ b/ui/locales/fr.json
@@ -0,0 +1,30 @@
+{
+  "FULL_SCREEN": "Plein écran",
+  "EXIT_FULL_SCREEN": "Quitter le mode plein écran",
+  "FAST_FORWARD": "Avance rapide",
+  "REWIND": "Retour arrière",
+  "MUTE": "Désactiver le son",
+  "UNMUTE": "Activer le son",
+  "PAUSE": "Mettre en veille",
+  "PLAY": "Lire",
+  "SEEK": "Barre de recherche",
+  "VOLUME": "volume",
+  "SKIP_TO_LIVE": "En direct",
+  "LIVE": "En direct",
+  "MORE_SETTINGS": "Autres paramètres",
+  "BACK": "Retour",
+  "CAPTIONS": "Sous-titres",
+  "RESOLUTION": "Résolution",
+  "AUTO_QUALITY": "Auto",
+  "CAST": "Caster sur…",
+  "LANGUAGE": "Langue",
+  "UNRECOGNIZED_LANGUAGE": "Inconnue",
+  "UNDETERMINED_LANGUAGE": "Inconnue",
+  "MULTIPLE_LANGUAGES": "plusieurs langues",
+  "NOT_APPLICABLE": "Non applicable",
+  "ENTER_PICTURE_IN_PICTURE": "utiliser le mode PIP",
+  "EXIT_PICTURE_IN_PICTURE": "quitter le mode PIP",
+  "PICTURE_IN_PICTURE": "Picture-in-picture",
+  "ON": "activé",
+  "OFF": "Désactivée"
+}
diff --git a/ui/locales/it.json b/ui/locales/it.json
new file mode 100644
index 0000000000..5907fae615
--- /dev/null
+++ b/ui/locales/it.json
@@ -0,0 +1,29 @@
+{
+  "FULL_SCREEN": "Schermo intero",
+  "EXIT_FULL_SCREEN": "Esci dalla modalità a schermo intero",
+  "FAST_FORWARD": "Avanti veloce",
+  "REWIND": "Riavvolgi",
+  "MUTE": "Disattiva audio",
+  "UNMUTE": "Riattiva audio",
+  "PAUSE": "Metti in pausa",
+  "PLAY": "Riproduci",
+  "SEEK": "Dispositivo di scorrimento",
+  "VOLUME": "volume",
+  "SKIP_TO_LIVE": "Dal vivo",
+  "LIVE": "Dal vivo",
+  "MORE_SETTINGS": "Altre impostazioni",
+  "BACK": "Indietro",
+  "CAPTIONS": "Sottotitoli",
+  "RESOLUTION": "Risoluzione",
+  "AUTO_QUALITY": "Auto",
+  "CAST": "Trasmetti…",
+  "LANGUAGE": "Lingua",
+  "UNRECOGNIZED_LANGUAGE": "Sconosciuto",
+  "UNDETERMINED_LANGUAGE": "Sconosciuto",
+  "NOT_APPLICABLE": "Non applicable",
+  "ENTER_PICTURE_IN_PICTURE": "attiva picture in picture",
+  "EXIT_PICTURE_IN_PICTURE": "esci da picture in picture",
+  "PICTURE_IN_PICTURE": "Picture in picture",
+  "ON": "on",
+  "OFF": "Disattivato"
+}
diff --git a/ui/locales/ja.json b/ui/locales/ja.json
new file mode 100644
index 0000000000..3610019f7b
--- /dev/null
+++ b/ui/locales/ja.json
@@ -0,0 +1,30 @@
+{
+  "FULL_SCREEN": "全画面",
+  "EXIT_FULL_SCREEN": "全画面モードの終了",
+  "FAST_FORWARD": "早送り",
+  "REWIND": "巻き戻し",
+  "MUTE": "ミュート",
+  "UNMUTE": "ミュート解除",
+  "PAUSE": "一時停止",
+  "PLAY": "再生",
+  "SEEK": "シーク バー",
+  "VOLUME": "音量",
+  "SKIP_TO_LIVE": "ライブ",
+  "LIVE": "ライブ",
+  "MORE_SETTINGS": "その他の設定",
+  "BACK": "戻る",
+  "CAPTIONS": "字幕",
+  "RESOLUTION": "解像度",
+  "AUTO_QUALITY": "自動",
+  "CAST": "キャスト...",
+  "LANGUAGE": "言語",
+  "UNRECOGNIZED_LANGUAGE": "不明",
+  "UNDETERMINED_LANGUAGE": "不明",
+  "MULTIPLE_LANGUAGES": "複数の言語",
+  "NOT_APPLICABLE": "--",
+  "ENTER_PICTURE_IN_PICTURE": "ピクチャー イン ピクチャーを開始します",
+  "EXIT_PICTURE_IN_PICTURE": "ピクチャー イン ピクチャーを終了します",
+  "PICTURE_IN_PICTURE": "ピクチャー イン ピクチャー",
+  "ON": "オン",
+  "OFF": "オフ"
+}
diff --git a/ui/locales/ko.json b/ui/locales/ko.json
new file mode 100644
index 0000000000..56268776db
--- /dev/null
+++ b/ui/locales/ko.json
@@ -0,0 +1,30 @@
+{
+  "FULL_SCREEN": "전체화면",
+  "EXIT_FULL_SCREEN": "전체화면 종료",
+  "FAST_FORWARD": "빨리감기",
+  "REWIND": "되감기",
+  "MUTE": "음소거",
+  "UNMUTE": "음소거 해제",
+  "PAUSE": "일시중지",
+  "PLAY": "재생",
+  "SEEK": "탐색 슬라이더",
+  "VOLUME": "볼륨",
+  "SKIP_TO_LIVE": "라이브",
+  "LIVE": "라이브",
+  "MORE_SETTINGS": "설정 더보기",
+  "BACK": "뒤로",
+  "CAPTIONS": "자막",
+  "RESOLUTION": "해상도",
+  "AUTO_QUALITY": "자동",
+  "CAST": "전송...",
+  "LANGUAGE": "언어",
+  "UNRECOGNIZED_LANGUAGE": "알 수 없음",
+  "UNDETERMINED_LANGUAGE": "알 수 없음",
+  "MULTIPLE_LANGUAGES": "여러 언어",
+  "NOT_APPLICABLE": "해당 사항 없음",
+  "ENTER_PICTURE_IN_PICTURE": "PIP 모드 시작",
+  "EXIT_PICTURE_IN_PICTURE": "PIP 모드 종료",
+  "PICTURE_IN_PICTURE": "PIP 모드",
+  "ON": "사용",
+  "OFF": "사용 안함"
+}
diff --git a/ui/locales/nl.json b/ui/locales/nl.json
new file mode 100644
index 0000000000..da2f4c4e17
--- /dev/null
+++ b/ui/locales/nl.json
@@ -0,0 +1,29 @@
+{
+  "FULL_SCREEN": "Volledig scherm",
+  "EXIT_FULL_SCREEN": "Volledig scherm afsluiten",
+  "FAST_FORWARD": "Vooruitspoelen",
+  "REWIND": "Terugspoelen",
+  "MUTE": "Dempen",
+  "UNMUTE": "Dempen opheffen",
+  "PAUSE": "Onderbreken",
+  "PLAY": "Afspelen",
+  "SEEK": "Zoekschuifbalk",
+  "VOLUME": "volume",
+  "SKIP_TO_LIVE": "Live",
+  "LIVE": "Live",
+  "MORE_SETTINGS": "Meer instellingen",
+  "BACK": "Terug",
+  "CAPTIONS": "Ondertiteling",
+  "RESOLUTION": "Resolutie",
+  "AUTO_QUALITY": "Automatisch",
+  "CAST": "Casten...",
+  "LANGUAGE": "Taal",
+  "UNRECOGNIZED_LANGUAGE": "Onbekend",
+  "UNDETERMINED_LANGUAGE": "Onbekend",
+  "NOT_APPLICABLE": "Niet van toepassing",
+  "ENTER_PICTURE_IN_PICTURE": "scherm-in-scherm openen",
+  "EXIT_PICTURE_IN_PICTURE": "scherm-in-scherm afsluiten",
+  "PICTURE_IN_PICTURE": "Scherm-in-scherm",
+  "ON": "aan",
+  "OFF": "Uit"
+}
diff --git a/ui/locales/pl.json b/ui/locales/pl.json
new file mode 100644
index 0000000000..f091c1df0f
--- /dev/null
+++ b/ui/locales/pl.json
@@ -0,0 +1,29 @@
+{
+  "FULL_SCREEN": "Pełny ekran",
+  "EXIT_FULL_SCREEN": "Zamknij pełny ekran",
+  "FAST_FORWARD": "Przewiń do przodu",
+  "REWIND": "Przewiń do tyłu",
+  "MUTE": "Wycisz",
+  "UNMUTE": "Wyłącz wyciszenie",
+  "PAUSE": "Wstrzymaj",
+  "PLAY": "Odtwarzaj",
+  "SEEK": "Suwak przewijania",
+  "VOLUME": "głośność",
+  "SKIP_TO_LIVE": "Na żywo",
+  "LIVE": "Na żywo",
+  "MORE_SETTINGS": "Więcej ustawień",
+  "BACK": "Wstecz",
+  "CAPTIONS": "Napisy",
+  "RESOLUTION": "Rozdzielczość",
+  "AUTO_QUALITY": "Automatyczna",
+  "CAST": "Prześlij...",
+  "LANGUAGE": "Język",
+  "UNRECOGNIZED_LANGUAGE": "Nieznane",
+  "UNDETERMINED_LANGUAGE": "Nieznane",
+  "NOT_APPLICABLE": "Nie dotyczy",
+  "ENTER_PICTURE_IN_PICTURE": "włącz tryb obrazu w obrazie",
+  "EXIT_PICTURE_IN_PICTURE": "wyłącz tryb obrazu w obrazie",
+  "PICTURE_IN_PICTURE": "Obraz w obrazie",
+  "ON": "wł.",
+  "OFF": "Wyłączone"
+}
diff --git a/ui/locales/pt-PT.json b/ui/locales/pt-PT.json
new file mode 100644
index 0000000000..d8cdf077b3
--- /dev/null
+++ b/ui/locales/pt-PT.json
@@ -0,0 +1,30 @@
+{
+  "FULL_SCREEN": "Ecrã inteiro",
+  "EXIT_FULL_SCREEN": "Sair do ecrã inteiro",
+  "FAST_FORWARD": "Avançar",
+  "REWIND": "Recuar",
+  "MUTE": "Desativar o som",
+  "UNMUTE": "Reativar o som",
+  "PAUSE": "Colocar em pausa",
+  "PLAY": "Reproduzir",
+  "SEEK": "Controlo de deslize da procura",
+  "VOLUME": "volume",
+  "SKIP_TO_LIVE": "Em direto",
+  "LIVE": "Em direto",
+  "MORE_SETTINGS": "Mais definições",
+  "BACK": "Anterior",
+  "CAPTIONS": "Legendas",
+  "RESOLUTION": "Resolução",
+  "AUTO_QUALITY": "Automático",
+  "CAST": "Transmitir...",
+  "LANGUAGE": "Idioma",
+  "UNRECOGNIZED_LANGUAGE": "Desconhecida",
+  "UNDETERMINED_LANGUAGE": "Desconhecida",
+  "MULTIPLE_LANGUAGES": "vários idiomas",
+  "NOT_APPLICABLE": "Não aplicável",
+  "ENTER_PICTURE_IN_PICTURE": "entrar no modo ecrã no ecrã",
+  "EXIT_PICTURE_IN_PICTURE": "sair do modo ecrã no ecrã",
+  "PICTURE_IN_PICTURE": "Ecrã no ecrã",
+  "ON": "ativado",
+  "OFF": "Desativado"
+}
diff --git a/ui/locales/pt.json b/ui/locales/pt.json
new file mode 100644
index 0000000000..c290e6668b
--- /dev/null
+++ b/ui/locales/pt.json
@@ -0,0 +1,30 @@
+{
+  "FULL_SCREEN": "Tela inteira",
+  "EXIT_FULL_SCREEN": "Sair da tela inteira",
+  "FAST_FORWARD": "Avançar",
+  "REWIND": "Retroceder",
+  "MUTE": "Desativar som",
+  "UNMUTE": "Ativar som",
+  "PAUSE": "Pausar",
+  "PLAY": "Reproduzir",
+  "SEEK": "Botão deslizante de busca",
+  "VOLUME": "volume",
+  "SKIP_TO_LIVE": "Ao vivo",
+  "LIVE": "Ao vivo",
+  "MORE_SETTINGS": "Mais configurações",
+  "BACK": "Voltar",
+  "CAPTIONS": "Legendas ocultas",
+  "RESOLUTION": "Resolução",
+  "AUTO_QUALITY": "Automático",
+  "CAST": "Elenco...",
+  "LANGUAGE": "Idioma",
+  "UNRECOGNIZED_LANGUAGE": "Desconhecido",
+  "UNDETERMINED_LANGUAGE": "Desconhecido",
+  "MULTIPLE_LANGUAGES": "vários idiomas",
+  "NOT_APPLICABLE": "Não aplicável",
+  "ENTER_PICTURE_IN_PICTURE": "entrar no modo picture-in-picture",
+  "EXIT_PICTURE_IN_PICTURE": "sair de picture-in-picture",
+  "PICTURE_IN_PICTURE": "Picture-in-picture",
+  "ON": "ativado",
+  "OFF": "Desativado"
+}
diff --git a/ui/locales/ru.json b/ui/locales/ru.json
new file mode 100644
index 0000000000..6134468004
--- /dev/null
+++ b/ui/locales/ru.json
@@ -0,0 +1,30 @@
+{
+  "FULL_SCREEN": "Во весь экран",
+  "EXIT_FULL_SCREEN": "Выход из полноэкранного режима",
+  "FAST_FORWARD": "Перемотать вперед",
+  "REWIND": "Перемотать назад",
+  "MUTE": "Отключить звук",
+  "UNMUTE": "Включить звук",
+  "PAUSE": "Приостановить",
+  "PLAY": "Смотреть",
+  "SEEK": "Ползунок поиска",
+  "VOLUME": "громкость",
+  "SKIP_TO_LIVE": "Смотреть прямой эфир",
+  "LIVE": "Прямой эфир",
+  "MORE_SETTINGS": "Дополнительные настройки",
+  "BACK": "Назад",
+  "CAPTIONS": "Субтитры",
+  "RESOLUTION": "Разрешение",
+  "AUTO_QUALITY": "Автонастройка",
+  "CAST": "Хромкаст",
+  "LANGUAGE": "Язык",
+  "UNRECOGNIZED_LANGUAGE": "Неизвестно",
+  "UNDETERMINED_LANGUAGE": "Неизвестно",
+  "MULTIPLE_LANGUAGES": "поддержка нескольких языков",
+  "NOT_APPLICABLE": "Неприменимо",
+  "ENTER_PICTURE_IN_PICTURE": "включить режим \"Картинка в картинке\"",
+  "EXIT_PICTURE_IN_PICTURE": "выйти из режима \"Картинка в картинке\"",
+  "PICTURE_IN_PICTURE": "Картинка в картинке",
+  "ON": "ВКЛ",
+  "OFF": "Выкл."
+}
diff --git a/ui/locales/source.json b/ui/locales/source.json
new file mode 100644
index 0000000000..86822937b0
--- /dev/null
+++ b/ui/locales/source.json
@@ -0,0 +1,124 @@
+{
+  "FULL_SCREEN": {
+    "message": "Full screen",
+    "description": "Label for a button used to enter full screen mode in the video player."
+  },
+  "EXIT_FULL_SCREEN": {
+    "message": "Exit full screen",
+    "description": "Label for a button used to exit full screen mode in the video player."
+  },
+  "FAST_FORWARD": {
+    "message": "Fast-forward",
+    "description": "Label for a button used to play video at a higher rate than normal."
+  },
+  "REWIND": {
+    "message": "Rewind",
+    "description": "Label for a button used to rewind video by seeking repeatedly backward."
+  },
+  "MUTE": {
+    "message": "Mute",
+    "description": "Label for a button used to mute the sound in the video player."
+  },
+  "UNMUTE": {
+    "message": "Unmute",
+    "description": "Label for a button used to unmute the sound in the video player."
+  },
+  "PAUSE": {
+    "message": "Pause",
+    "description": "Label for a button used to pause a video in the video player."
+  },
+  "PLAY": {
+    "message": "Play",
+    "description": "Label for a button used to play or unpause video in a video player."
+  },
+  "SEEK": {
+    "message": "Seek",
+    "description": "Label for a slider used to show progress or seek to a particular time in a video."
+  },
+  "VOLUME": {
+    "message": "Volume",
+    "description": "Label for a slider used to set the volume level of the video player."
+  },
+  "SKIP_TO_LIVE": {
+    "message": "Skip ahead to live",
+    "description": "Label for a button used to skip ahead to the live edge of a live video stream."
+  },
+  "LIVE": {
+    "message": "Live",
+    "description": "Label to indicate that a video is already playing at the live edge of a live video stream."
+  },
+  "MORE_SETTINGS": {
+    "message": "More settings",
+    "description": "Label for a button used to open a menu with additional settings in the video player."
+  },
+
+  "BACK": {
+    "message": "Back",
+    "meaning": "Return to previous menu",
+    "description": "Label for a button used to return to the previous menu in the video player's settings."
+  },
+
+  "CAPTIONS": {
+    "message": "Captions",
+    "description": "Label for a button used to navigate to a submenu to choose captions/subtitles in the video player."
+  },
+
+  "RESOLUTION": {
+    "message": "Resolution",
+    "meaning": "Visual quality",
+    "description": "Label for a button used to open a submenu to choose a video resolution in the video player."
+  },
+  "AUTO_QUALITY": {
+    "message": "Auto",
+    "meaning": "Automatic",
+    "description": "Label for a button used to allow the video player to select the resolution/quality of the video automatically."
+  },
+
+  "CAST": {
+    "message": "Cast...",
+    "description": "Label for a button used to open the native Cast dialog in the browser and select a destination to Cast to."
+  },
+
+  "LANGUAGE": {
+    "message": "Language",
+    "description": "Label for a button used to navigate to a submenu to choose the audio language in the video player."
+  },
+  "UNRECOGNIZED_LANGUAGE": {
+    "message": "Unrecognized",
+    "description": "Label for a button used to select an audio language whose language code we do not recognize.  This will be followed by the language code in parentheses.  For example, \"Unrecognized (sjn)\"."
+  },
+  "UNDETERMINED_LANGUAGE": {
+    "message": "Undetermined",
+    "description": "Label for a button used to select an audio track whose language is undetermined or unknown."
+  },
+  "MULTIPLE_LANGUAGES": {
+    "message": "Multiple languages",
+    "description": "Label for a button used to select an audio track which contains content in multiple languages."
+  },
+  "NOT_APPLICABLE": {
+    "message": "Not applicable",
+    "description": "Label for a button used to select an audio track for which language is not applicable, such as content without spoken words."
+  },
+
+  "ENTER_PICTURE_IN_PICTURE": {
+    "message": "Enter Picture-in-Picture",
+    "description": "Label for a button used to enter Picture-in-Picture mode in a video player.  This mode will float the video on top of the user's desktop and allow them to continue viewing while using other applications."
+  },
+  "EXIT_PICTURE_IN_PICTURE": {
+    "message": "Exit Picture-in-Picture",
+    "description": "Label for a button used to exit Picture-in-Picture mode in a video player.  This will bring the video back into the web page, rather than floating on top of the user's desktop."
+  },
+  "PICTURE_IN_PICTURE": {
+    "message": "Picture-in-Picture",
+    "description": "Label for a button used to control the Picture-in-Picture mode of a video player.  This mode will float the video on top of the user's desktop and allow them to continue viewing while using other applications."
+  },
+
+  "ON": {
+    "message": "On",
+    "description": "Title beneath a button showing that this feature of the video player is current enabled.  Currently used for Picture-in-Picture, but could apply to other features in the future."
+  },
+  "OFF": {
+    "message": "Off",
+    "description": "Title beneath a button showing that this feature of the video player is not currently enabled.  Currently used for Cast, Picture-in-Picture, and Captions/Subtitles, but could apply to other features in the future."
+  }
+}
diff --git a/ui/locales/th.json b/ui/locales/th.json
new file mode 100644
index 0000000000..7d636134e4
--- /dev/null
+++ b/ui/locales/th.json
@@ -0,0 +1,29 @@
+{
+  "FULL_SCREEN": "เต็มหน้าจอ",
+  "EXIT_FULL_SCREEN": "ออกจากโหมดเต็มหน้าจอ",
+  "FAST_FORWARD": "กรอไปข้างหน้า",
+  "REWIND": "กรอกลับ",
+  "MUTE": "ปิดเสียง",
+  "UNMUTE": "เปิดเสียง",
+  "PAUSE": "หยุดชั่วคราว",
+  "PLAY": "เล่น",
+  "SEEK": "แถบเลื่อนค้นหา",
+  "VOLUME": "ระดับเสียง",
+  "SKIP_TO_LIVE": "สด",
+  "LIVE": "สด",
+  "MORE_SETTINGS": "การตั้งค่าเพิ่มเติม",
+  "BACK": "กลับ",
+  "CAPTIONS": "คำอธิบายวิดีโอ",
+  "RESOLUTION": "ความละเอียด",
+  "AUTO_QUALITY": "อัตโนมัติ",
+  "CAST": "แคสต์...",
+  "LANGUAGE": "ภาษา",
+  "UNRECOGNIZED_LANGUAGE": "ไม่ทราบ",
+  "UNDETERMINED_LANGUAGE": "ไม่ทราบ",
+  "NOT_APPLICABLE": "ไม่เกี่ยวข้อง",
+  "ENTER_PICTURE_IN_PICTURE": "เข้าสู่การแสดงภาพซ้อนภาพ",
+  "EXIT_PICTURE_IN_PICTURE": "ออกจากการแสดงภาพซ้อนภาพ",
+  "PICTURE_IN_PICTURE": "การแสดงภาพซ้อนภาพ",
+  "ON": "เปิด",
+  "OFF": "ปิด"
+}
diff --git a/ui/locales/tr.json b/ui/locales/tr.json
new file mode 100644
index 0000000000..8714a9fc9a
--- /dev/null
+++ b/ui/locales/tr.json
@@ -0,0 +1,29 @@
+{
+  "FULL_SCREEN": "Tam ekran",
+  "EXIT_FULL_SCREEN": "Tam ekrandan çık",
+  "FAST_FORWARD": "İleri sar",
+  "REWIND": "Geri sar",
+  "MUTE": "Sesi kapat",
+  "UNMUTE": "Sesi aç",
+  "PAUSE": "Duraklat",
+  "PLAY": "Oynat",
+  "SEEK": "Arama kaydırma çubuğu",
+  "VOLUME": "ses düzeyi",
+  "SKIP_TO_LIVE": "Canlı",
+  "LIVE": "Canlı",
+  "MORE_SETTINGS": "Diğer ayarlar",
+  "BACK": "Geri",
+  "CAPTIONS": "Altyazılar",
+  "RESOLUTION": "Çözünürlük",
+  "AUTO_QUALITY": "Otomatik",
+  "CAST": "Yayınla...",
+  "LANGUAGE": "Dil",
+  "UNRECOGNIZED_LANGUAGE": "Bilinmiyor",
+  "UNDETERMINED_LANGUAGE": "Bilinmiyor",
+  "NOT_APPLICABLE": "Kullanılmıyor",
+  "ENTER_PICTURE_IN_PICTURE": "pencere içinde pencere moduna gir",
+  "EXIT_PICTURE_IN_PICTURE": "pencere içinde pencere modundan çıkın",
+  "PICTURE_IN_PICTURE": "Pencere içinde Pencere",
+  "ON": "açık",
+  "OFF": "Kapalı"
+}
diff --git a/ui/locales/zh-HK.json b/ui/locales/zh-HK.json
new file mode 100644
index 0000000000..e400c30655
--- /dev/null
+++ b/ui/locales/zh-HK.json
@@ -0,0 +1,30 @@
+{
+  "FULL_SCREEN": "全螢幕",
+  "EXIT_FULL_SCREEN": "結束全螢幕",
+  "FAST_FORWARD": "快轉",
+  "REWIND": "倒帶",
+  "MUTE": "靜音",
+  "UNMUTE": "解除靜音",
+  "PAUSE": "暫停",
+  "PLAY": "播放",
+  "SEEK": "搜尋滑桿",
+  "VOLUME": "音量",
+  "SKIP_TO_LIVE": "直播",
+  "LIVE": "直播",
+  "MORE_SETTINGS": "更多設定",
+  "BACK": "返回",
+  "CAPTIONS": "字幕",
+  "RESOLUTION": "",
+  "AUTO_QUALITY": "自動",
+  "CAST": "投放…",
+  "LANGUAGE": "語言",
+  "UNRECOGNIZED_LANGUAGE": "不明",
+  "UNDETERMINED_LANGUAGE": "不明",
+  "MULTIPLE_LANGUAGES": "多種語言",
+  "NOT_APPLICABLE": "不適用",
+  "ENTER_PICTURE_IN_PICTURE": "進入畫中畫",
+  "EXIT_PICTURE_IN_PICTURE": "退出畫中畫",
+  "PICTURE_IN_PICTURE": "畫中畫",
+  "ON": "",
+  "OFF": "未選取"
+}
diff --git a/ui/locales/zh-TW.json b/ui/locales/zh-TW.json
new file mode 100644
index 0000000000..6f1d12f0b2
--- /dev/null
+++ b/ui/locales/zh-TW.json
@@ -0,0 +1,29 @@
+{
+  "FULL_SCREEN": "全螢幕",
+  "EXIT_FULL_SCREEN": "結束全螢幕",
+  "FAST_FORWARD": "快轉",
+  "REWIND": "倒轉",
+  "MUTE": "靜音",
+  "UNMUTE": "解除靜音",
+  "PAUSE": "暫停",
+  "PLAY": "播放",
+  "SEEK": "搜尋滑桿",
+  "VOLUME": "音量",
+  "SKIP_TO_LIVE": "直播",
+  "LIVE": "直播",
+  "MORE_SETTINGS": "更多設定",
+  "BACK": "返回",
+  "CAPTIONS": "字幕",
+  "RESOLUTION": "解析度",
+  "AUTO_QUALITY": "自動",
+  "CAST": "投放…",
+  "LANGUAGE": "語言",
+  "UNRECOGNIZED_LANGUAGE": "未知",
+  "UNDETERMINED_LANGUAGE": "未知",
+  "NOT_APPLICABLE": "不適用",
+  "ENTER_PICTURE_IN_PICTURE": "進入子母畫面",
+  "EXIT_PICTURE_IN_PICTURE": "離開子母畫面",
+  "PICTURE_IN_PICTURE": "子母畫面",
+  "ON": "開啟",
+  "OFF": "關閉"
+}
diff --git a/ui/locales/zh.json b/ui/locales/zh.json
new file mode 100644
index 0000000000..4999becfa5
--- /dev/null
+++ b/ui/locales/zh.json
@@ -0,0 +1,29 @@
+{
+  "FULL_SCREEN": "全屏",
+  "EXIT_FULL_SCREEN": "退出全屏",
+  "FAST_FORWARD": "快进",
+  "REWIND": "快退",
+  "MUTE": "静音",
+  "UNMUTE": "取消静音",
+  "PAUSE": "暂停",
+  "PLAY": "播放",
+  "SEEK": "播放滑块",
+  "VOLUME": "音量",
+  "SKIP_TO_LIVE": "直播",
+  "LIVE": "直播",
+  "MORE_SETTINGS": "更多设置",
+  "BACK": "返回",
+  "CAPTIONS": "字幕",
+  "RESOLUTION": "分辨率",
+  "AUTO_QUALITY": "自动",
+  "CAST": "投射…",
+  "LANGUAGE": "语言",
+  "UNRECOGNIZED_LANGUAGE": "未知",
+  "UNDETERMINED_LANGUAGE": "未知",
+  "NOT_APPLICABLE": "不適用",
+  "ENTER_PICTURE_IN_PICTURE": "进入“画中画”模式",
+  "EXIT_PICTURE_IN_PICTURE": "退出“画中画”模式",
+  "PICTURE_IN_PICTURE": "画中画",
+  "ON": "开启",
+  "OFF": "关闭"
+}
diff --git a/ui/mute_button.js b/ui/mute_button.js
index 186ead9835..d5cb33b2c2 100644
--- a/ui/mute_button.js
+++ b/ui/mute_button.js
@@ -71,8 +71,7 @@ shaka.ui.MuteButton = class extends shaka.ui.Element {
    */
   updateAriaLabel_() {
     const LocIds = shaka.ui.Locales.Ids;
-    const label =
-      this.video.muted ? LocIds.ARIA_LABEL_UNMUTE : LocIds.ARIA_LABEL_MUTE;
+    const label = this.video.muted ? LocIds.UNMUTE : LocIds.MUTE;
 
     this.button_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
         this.localization.resolve(label));
diff --git a/ui/overflow_menu.js b/ui/overflow_menu.js
index 30cd1551f1..e388644f1a 100644
--- a/ui/overflow_menu.js
+++ b/ui/overflow_menu.js
@@ -202,7 +202,7 @@ goog.require('shaka.util.Dom');
   updateAriaLabel_() {
     const LocIds = shaka.ui.Locales.Ids;
     this.overflowMenuButton_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
-        this.localization.resolve(LocIds.ARIA_LABEL_MORE_SETTINGS));
+        this.localization.resolve(LocIds.MORE_SETTINGS));
   }
 };
 
diff --git a/ui/pip_button.js b/ui/pip_button.js
index 63e7716420..90694f09d9 100644
--- a/ui/pip_button.js
+++ b/ui/pip_button.js
@@ -57,7 +57,7 @@ shaka.ui.PipButton = class extends shaka.ui.Element {
     label.classList.add('shaka-overflow-button-label');
     this.pipNameSpan_ = shaka.util.Dom.createHTMLElement('span');
     this.pipNameSpan_.textContent =
-      this.localization.resolve(LocIds.LABEL_PICTURE_IN_PICTURE);
+      this.localization.resolve(LocIds.PICTURE_IN_PICTURE);
     label.appendChild(this.pipNameSpan_);
 
     /** @private {!HTMLElement} */
@@ -144,9 +144,9 @@ shaka.ui.PipButton = class extends shaka.ui.Element {
     const LocIds = shaka.ui.Locales.Ids;
     this.pipIcon_.textContent = shaka.ui.Enums.MaterialDesignIcons.EXIT_PIP;
     this.pipButton_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
-        this.localization.resolve(LocIds.ARIA_LABEL_EXIT_PICTURE_IN_PICTURE));
+        this.localization.resolve(LocIds.EXIT_PICTURE_IN_PICTURE));
     this.currentPipState_.textContent =
-        this.localization.resolve(LocIds.LABEL_PICTURE_IN_PICTURE_ON);
+        this.localization.resolve(LocIds.ON);
   }
 
 
@@ -155,9 +155,9 @@ shaka.ui.PipButton = class extends shaka.ui.Element {
     const LocIds = shaka.ui.Locales.Ids;
     this.pipIcon_.textContent = shaka.ui.Enums.MaterialDesignIcons.PIP;
     this.pipButton_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
-        this.localization.resolve(LocIds.ARIA_LABEL_ENTER_PICTURE_IN_PICTURE));
+        this.localization.resolve(LocIds.ENTER_PICTURE_IN_PICTURE));
     this.currentPipState_.textContent =
-        this.localization.resolve(LocIds.LABEL_PICTURE_IN_PICTURE_OFF);
+        this.localization.resolve(LocIds.OFF);
   }
 
 
@@ -168,17 +168,16 @@ shaka.ui.PipButton = class extends shaka.ui.Element {
     const LocIds = shaka.ui.Locales.Ids;
 
     this.pipNameSpan_.textContent =
-      this.localization.resolve(LocIds.LABEL_PICTURE_IN_PICTURE);
+      this.localization.resolve(LocIds.PICTURE_IN_PICTURE);
 
     const ariaLabel = document.pictureInPictureElement ?
-                         LocIds.ARIA_LABEL_EXIT_PICTURE_IN_PICTURE :
-                         LocIds.ARIA_LABEL_ENTER_PICTURE_IN_PICTURE;
+        LocIds.EXIT_PICTURE_IN_PICTURE :
+        LocIds.ENTER_PICTURE_IN_PICTURE;
     this.pipButton_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
         this.localization.resolve(ariaLabel));
 
     const currentPipState = document.pictureInPictureElement ?
-                            LocIds.LABEL_PICTURE_IN_PICTURE_ON :
-                            LocIds.LABEL_PICTURE_IN_PICTURE_OFF;
+        LocIds.ON : LocIds.OFF;
 
     this.currentPipState_.textContent =
         this.localization.resolve(currentPipState);
diff --git a/ui/presentation_time.js b/ui/presentation_time.js
index 7e7bc407f3..ee38cdb56e 100644
--- a/ui/presentation_time.js
+++ b/ui/presentation_time.js
@@ -85,7 +85,7 @@ shaka.ui.PresentationTimeTracker = class extends shaka.ui.Element {
         this.currentTime_.disabled = false;
       } else {
         this.currentTime_.textContent =
-          this.localization.resolve(shaka.ui.Locales.Ids.LABEL_LIVE);
+            this.localization.resolve(shaka.ui.Locales.Ids.LIVE);
         this.currentTime_.disabled = true;
       }
     } else {
@@ -129,7 +129,7 @@ shaka.ui.PresentationTimeTracker = class extends shaka.ui.Element {
    */
   onTracksChanged_() {
     if (this.player.isLive()) {
-      const ariaLabel = shaka.ui.Locales.Ids.ARIA_LABEL_LIVE;
+      const ariaLabel = shaka.ui.Locales.Ids.SKIP_TO_LIVE;
       this.currentTime_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
           this.localization.resolve(ariaLabel));
     }
diff --git a/ui/resolution_selection.js b/ui/resolution_selection.js
index 76ca7bd3e2..c7c31eefd4 100644
--- a/ui/resolution_selection.js
+++ b/ui/resolution_selection.js
@@ -226,7 +226,7 @@ shaka.ui.ResolutionSelection = class extends shaka.ui.Element {
 
     const autoSpan = shaka.util.Dom.createHTMLElement('span');
     autoSpan.textContent =
-      this.localization.resolve(shaka.ui.Locales.Ids.LABEL_AUTO_QUALITY);
+        this.localization.resolve(shaka.ui.Locales.Ids.AUTO_QUALITY);
     autoButton.appendChild(autoSpan);
 
     // If abr is enabled reflect it by marking 'Auto' as selected.
@@ -237,7 +237,7 @@ shaka.ui.ResolutionSelection = class extends shaka.ui.Element {
       autoSpan.classList.add('shaka-chosen-item');
 
       this.currentResolution_.textContent =
-        this.localization.resolve(shaka.ui.Locales.Ids.LABEL_AUTO_QUALITY);
+          this.localization.resolve(shaka.ui.Locales.Ids.AUTO_QUALITY);
     }
 
     this.resolutionMenu_.appendChild(autoButton);
@@ -272,15 +272,15 @@ shaka.ui.ResolutionSelection = class extends shaka.ui.Element {
     const LocIds = shaka.ui.Locales.Ids;
 
     this.resolutionButton_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
-        this.localization.resolve(LocIds.ARIA_LABEL_RESOLUTION));
+        this.localization.resolve(LocIds.RESOLUTION));
     this.backFromResolutionButton_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
-        this.localization.resolve(LocIds.ARIA_LABEL_RESOLUTION));
+        this.localization.resolve(LocIds.RESOLUTION));
     this.backFromResolutionSpan_.textContent =
-      this.localization.resolve(LocIds.LABEL_RESOLUTION);
+        this.localization.resolve(LocIds.RESOLUTION);
     this.resolutionNameSpan_.textContent =
-      this.localization.resolve(LocIds.LABEL_RESOLUTION);
+        this.localization.resolve(LocIds.RESOLUTION);
     this.abrOnSpan_.textContent =
-      this.localization.resolve(LocIds.LABEL_AUTO_QUALITY);
+        this.localization.resolve(LocIds.AUTO_QUALITY);
   }
 };
 
diff --git a/ui/rewind_button.js b/ui/rewind_button.js
index 31b3aa8e8b..fbec666f5d 100644
--- a/ui/rewind_button.js
+++ b/ui/rewind_button.js
@@ -67,7 +67,7 @@ shaka.ui.RewindButton = class extends shaka.ui.Element {
    */
   updateAriaLabel_() {
     this.button_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
-        this.localization.resolve(shaka.ui.Locales.Ids.ARIA_LABEL_REWIND));
+        this.localization.resolve(shaka.ui.Locales.Ids.REWIND));
   }
 
   /**
diff --git a/ui/text_selection.js b/ui/text_selection.js
index cfad47269c..e62eda903d 100644
--- a/ui/text_selection.js
+++ b/ui/text_selection.js
@@ -225,7 +225,7 @@ shaka.ui.TextSelection = class extends shaka.ui.Element {
       offButton.appendChild(shaka.ui.Utils.checkmarkIcon());
       this.captionsOffSpan_.classList.add('shaka-chosen-item');
       this.currentCaptions_.textContent =
-          this.localization.resolve(shaka.ui.Locales.Ids.LABEL_CAPTIONS_OFF);
+          this.localization.resolve(shaka.ui.Locales.Ids.OFF);
     }
 
     shaka.ui.Utils.focusOnTheChosenItem(this.textLangMenu_);
@@ -254,15 +254,15 @@ shaka.ui.TextSelection = class extends shaka.ui.Element {
     const LocIds = shaka.ui.Locales.Ids;
 
     this.captionButton_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
-        this.localization.resolve(LocIds.ARIA_LABEL_CAPTIONS));
+        this.localization.resolve(LocIds.CAPTIONS));
     this.backFromCaptionsButton_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
-        this.localization.resolve(LocIds.ARIA_LABEL_BACK));
+        this.localization.resolve(LocIds.BACK));
     this.captionsNameSpan_.textContent =
-      this.localization.resolve(LocIds.LABEL_CAPTIONS);
+        this.localization.resolve(LocIds.CAPTIONS);
     this.backFromCaptionsSpan_.textContent =
-      this.localization.resolve(LocIds.LABEL_CAPTIONS);
+        this.localization.resolve(LocIds.CAPTIONS);
     this.captionsOffSpan_.textContent =
-      this.localization.resolve(LocIds.LABEL_CAPTIONS_OFF);
+        this.localization.resolve(LocIds.OFF);
   }
 
 
diff --git a/ui/volume_bar.js b/ui/volume_bar.js
index bf53a58771..65505e4ce0 100644
--- a/ui/volume_bar.js
+++ b/ui/volume_bar.js
@@ -120,7 +120,7 @@ shaka.ui.VolumeBar = class extends shaka.ui.Element {
    */
   updateAriaLabel_() {
     this.bar_.setAttribute(shaka.ui.Constants.ARIA_LABEL,
-        this.localization.resolve(shaka.ui.Locales.Ids.ARIA_LABEL_VOLUME));
+        this.localization.resolve(shaka.ui.Locales.Ids.VOLUME));
   }
 };