diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
index 43e1c3996712..9a8e6812cf31 100644
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -12,19 +12,18 @@
 
 ## Checklist:
   - [ ] The code change is tested and works locally.
+  - [ ] Local tests pass with `tox`. **Your PR cannot be merged unless tests pass**
 
 If user exposed functionality or configuration variables are added/changed:
   - [ ] Documentation added/updated in [home-assistant.github.io](https://github.com/home-assistant/home-assistant.github.io)
 
 If the code communicates with devices, web services, or third-party tools:
-  - [ ] Local tests with `tox` run successfully. **Your PR cannot be merged unless tests pass**
   - [ ] New dependencies have been added to the `REQUIREMENTS` variable ([example][ex-requir]).
   - [ ] New dependencies are only imported inside functions that use them ([example][ex-import]).
   - [ ] New dependencies have been added to `requirements_all.txt` by running `script/gen_requirements_all.py`.
   - [ ] New files were added to `.coveragerc`.
 
 If the code does not interact with devices:
-  - [ ] Local tests with `tox` run successfully. **Your PR cannot be merged unless tests pass**
   - [ ] Tests have been added to verify that the new code works.
 
 [ex-requir]: https://github.com/home-assistant/home-assistant/blob/dev/homeassistant/components/keyboard.py#L14
diff --git a/script/gen_requirements_all.py b/script/gen_requirements_all.py
index a9a68d09491c..a7704088e265 100755
--- a/script/gen_requirements_all.py
+++ b/script/gen_requirements_all.py
@@ -277,23 +277,23 @@ def validate_constraints_file(data):
         return data + CONSTRAINT_BASE == req_file.read()
 
 
-def main():
+def main(validate):
     """Main section of the script."""
     if not os.path.isfile('requirements_all.txt'):
         print('Run this from HA root dir')
-        return
+        return 1
 
     data = gather_modules()
 
     if data is None:
-        sys.exit(1)
+        return 1
 
     constraints = gather_constraints()
 
     reqs_file = requirements_all_output(data)
     reqs_test_file = requirements_test_output(data)
 
-    if sys.argv[-1] == 'validate':
+    if validate:
         errors = []
         if not validate_requirements_file(reqs_file):
             errors.append("requirements_all.txt is not up to date")
@@ -309,14 +309,16 @@ def main():
             print("******* ERROR")
             print('\n'.join(errors))
             print("Please run script/gen_requirements_all.py")
-            sys.exit(1)
+            return 1
 
-        sys.exit(0)
+        return 0
 
     write_requirements_file(reqs_file)
     write_test_requirements_file(reqs_test_file)
     write_constraints_file(constraints)
+    return 0
 
 
 if __name__ == '__main__':
-    main()
+    _VAL = sys.argv[-1] == 'validate'
+    sys.exit(main(_VAL))
diff --git a/script/lazytox.py b/script/lazytox.py
new file mode 100644
index 000000000000..2137ae1794c5
--- /dev/null
+++ b/script/lazytox.py
@@ -0,0 +1,235 @@
+#!/usr/bin/env python3
+"""
+Lazy 'tox' to quickly check if branch is up to PR standards.
+
+This is NOT a tox replacement, only a quick check during development.
+"""
+import os
+import asyncio
+import sys
+import re
+import shlex
+from collections import namedtuple
+
+try:
+    from colorlog.escape_codes import escape_codes
+except ImportError:
+    escape_codes = None
+
+
+RE_ASCII = re.compile(r"\033\[[^m]*m")
+Error = namedtuple('Error', ['file', 'line', 'col', 'msg'])
+
+PASS = 'green'
+FAIL = 'bold_red'
+
+
+def printc(the_color, *args):
+    """Color print helper."""
+    msg = ' '.join(args)
+    if not escape_codes:
+        print(msg)
+        return
+    try:
+        print(escape_codes[the_color] + msg + escape_codes['reset'])
+    except KeyError:
+        print(msg)
+        raise ValueError("Invalid color {}".format(the_color))
+
+
+def validate_requirements_ok():
+    """Validate requirements, returns True of ok."""
+    # pylint: disable=E0402
+    from gen_requirements_all import main as req_main
+    return req_main(True) == 0
+
+
+async def read_stream(stream, display):
+    """Read from stream line by line until EOF, display, and capture lines."""
+    output = []
+    while True:
+        line = await stream.readline()
+        if not line:
+            break
+        output.append(line)
+        display(line.decode())  # assume it doesn't block
+    return b''.join(output)
+
+
+async def async_exec(*args, display=False):
+    """Execute, return code & log."""
+    argsp = []
+    for arg in args:
+        if os.path.isfile(arg):
+            argsp.append("\\\n  {}".format(shlex.quote(arg)))
+        else:
+            argsp.append(shlex.quote(arg))
+    printc('cyan', *argsp)
+    try:
+        kwargs = {'loop': LOOP, 'stdout': asyncio.subprocess.PIPE,
+                  'stderr': asyncio.subprocess.STDOUT}
+        if display:
+            kwargs['stderr'] = asyncio.subprocess.PIPE
+        # pylint: disable=E1120
+        proc = await asyncio.create_subprocess_exec(*args, **kwargs)
+    except FileNotFoundError as err:
+        printc(FAIL, "Could not execute {}. Did you install test requirements?"
+               .format(args[0]))
+        raise err
+
+    if not display:
+        # Readin stdout into log
+        stdout, _ = await proc.communicate()
+    else:
+        # read child's stdout/stderr concurrently (capture and display)
+        stdout, _ = await asyncio.gather(
+            read_stream(proc.stdout, sys.stdout.write),
+            read_stream(proc.stderr, sys.stderr.write))
+    exit_code = await proc.wait()
+    stdout = stdout.decode('utf-8')
+    return exit_code, stdout
+
+
+async def git():
+    """Exec git."""
+    if len(sys.argv) > 2 and sys.argv[1] == '--':
+        return sys.argv[2:]
+    _, log = await async_exec('git', 'diff', 'upstream/dev...', '--name-only')
+    return log.splitlines()
+
+
+async def pylint(files):
+    """Exec pylint."""
+    _, log = await async_exec('pylint', '-f', 'parseable', '--persistent=n',
+                              *files)
+    res = []
+    for line in log.splitlines():
+        line = line.split(':')
+        if len(line) < 3:
+            continue
+        res.append(Error(line[0].replace('\\', '/'),
+                         line[1], "", line[2].strip()))
+    return res
+
+
+async def flake8(files):
+    """Exec flake8."""
+    _, log = await async_exec('flake8', '--doctests', *files)
+    res = []
+    for line in log.splitlines():
+        line = line.split(':')
+        if len(line) < 4:
+            continue
+        res.append(Error(line[0].replace('\\', '/'),
+                         line[1], line[2], line[3].strip()))
+    return res
+
+
+async def lint(files):
+    """Perform lint."""
+    fres, pres = await asyncio.gather(flake8(files), pylint(files))
+
+    res = fres + pres
+    res.sort(key=lambda item: item.file)
+    if res:
+        print("Pylint & Flake8 errors:")
+    else:
+        printc(PASS, "Pylint and Flake8 passed")
+
+    lint_ok = True
+    for err in res:
+        err_msg = "{} {}:{} {}".format(err.file, err.line, err.col, err.msg)
+
+        # tests/* does not have to pass lint
+        if err.file.startswith('tests/'):
+            print(err_msg)
+        else:
+            printc(FAIL, err_msg)
+            lint_ok = False
+
+    return lint_ok
+
+
+async def main():
+    """The main loop."""
+    # Ensure we are in the homeassistant root
+    os.chdir(os.path.dirname(os.path.dirname(os.path.realpath(__file__))))
+
+    files = await git()
+    if not files:
+        print("No changed files found. Please ensure you have added your "
+              "changes with git add & git commit")
+        return
+
+    pyfile = re.compile(r".+\.py$")
+    pyfiles = [file for file in files if pyfile.match(file)]
+
+    print("=============================")
+    printc('bold', "CHANGED FILES:\n", '\n '.join(pyfiles))
+    print("=============================")
+
+    skip_lint = len(sys.argv) > 1 and sys.argv[1] == '--skiplint'
+    if skip_lint:
+        printc(FAIL, "LINT DISABLED")
+    elif not await lint(pyfiles):
+        printc(FAIL, "Please fix your lint issues before continuing")
+        return
+
+    test_files = set()
+    gen_req = False
+    for fname in pyfiles:
+        if fname.startswith('homeassistant/components/'):
+            gen_req = True  # requirements script for components
+        # Find test files...
+        if fname.startswith('tests/'):
+            if '/test_' in fname:  # All test helpers should be excluded
+                test_files.add(fname)
+        else:
+            parts = fname.split('/')
+            parts[0] = 'tests'
+            if parts[-1] == '__init__.py':
+                parts[-1] = 'test_init.py'
+            elif parts[-1] == '__main__.py':
+                parts[-1] = 'test_main.py'
+            else:
+                parts[-1] = 'test_' + parts[-1]
+            fname = '/'.join(parts)
+            if os.path.isfile(fname):
+                test_files.add(fname)
+
+    if gen_req:
+        print("=============================")
+        if validate_requirements_ok():
+            printc(PASS, "script/gen_requirements.py passed")
+        else:
+            printc(FAIL, "Please run script/gen_requirements.py")
+            return
+
+    print("=============================")
+    if not test_files:
+        print("No test files identified, ideally you should run tox")
+        return
+
+    code, _ = await async_exec(
+        'pytest', '-vv', '--force-sugar', '--', *test_files, display=True)
+    print("=============================")
+
+    if code == 0:
+        printc(PASS, "Yay! This will most likely pass tox")
+    else:
+        printc(FAIL, "Tests not passing")
+
+    if skip_lint:
+        printc(FAIL, "LINT DISABLED")
+
+
+if __name__ == '__main__':
+    LOOP = asyncio.ProactorEventLoop() if sys.platform == 'win32' \
+        else asyncio.get_event_loop()
+
+    try:
+        LOOP.run_until_complete(main())
+    except (FileNotFoundError, KeyboardInterrupt):
+        pass
+    finally:
+        LOOP.close()
diff --git a/script/lint b/script/lint
index bfce996788eb..9d994429f740 100755
--- a/script/lint
+++ b/script/lint
@@ -3,25 +3,21 @@
 
 cd "$(dirname "$0")/.."
 
-if [ "$1" = "--all" ]; then
-  tox -e lint
-else
-  export files="`git diff upstream/dev... --name-only | grep -e '\.py$'`"
-  echo "================================================="
-  echo "FILES CHANGED (git diff upstream/dev... --name-only)"
-  echo "================================================="
-  if [ -z "$files" ] ; then
-    echo "No python file changed"
-    exit
-  fi
-  printf "%s\n" $files
-  echo "================"
-  echo "LINT with flake8"
-  echo "================"
-  flake8 --doctests $files
-  echo "================"
-  echo "LINT with pylint"
-  echo "================"
-  pylint $files
-  echo
+export files="`git diff upstream/dev... --name-only | grep -e '\.py$'`"
+echo "================================================="
+echo "FILES CHANGED (git diff upstream/dev... --name-only)"
+echo "================================================="
+if [ -z "$files" ] ; then
+  echo "No python file changed. Rather use: tox -e lint"
+  exit
 fi
+printf "%s\n" $files
+echo "================"
+echo "LINT with flake8"
+echo "================"
+flake8 --doctests $files
+echo "================"
+echo "LINT with pylint"
+echo "================"
+pylint $files
+echo