diff --git a/lib/wavesync.rb b/lib/wavesync.rb
index 67e2239..38a3a36 100644
--- a/lib/wavesync.rb
+++ b/lib/wavesync.rb
@@ -9,6 +9,7 @@ module Wavesync
 require 'wavesync/device'
 require 'wavesync/ui'
 require 'wavesync/path_resolver'
+require 'wavesync/file_converter'
 require 'wavesync/scanner'
 require 'wavesync/bpm_detector'
 require 'wavesync/analyzer'
diff --git a/lib/wavesync/file_converter.rb b/lib/wavesync/file_converter.rb
new file mode 100644
index 0000000..23e37e6
--- /dev/null
+++ b/lib/wavesync/file_converter.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+module Wavesync
+  class FileConverter
+    def convert(audio, source_file_path, path_resolver, target_file_type, _source_sample_rate,
+                target_sample_rate, source_bit_depth, target_bit_depth, &before_transcode)
+      return false unless target_file_type || target_sample_rate || target_bit_depth
+
+      target_path = path_resolver.resolve(source_file_path, audio, target_file_type: target_file_type)
+
+      files_to_cleanup = path_resolver.find_files_to_cleanup(target_path, audio)
+      files_to_cleanup.each { |file| FileUtils.rm_f(file) }
+
+      if target_file_type
+        source_converted_path = Pathname(source_file_path).sub_ext(".#{target_file_type}")
+        return false if source_converted_path.exist?
+      end
+
+      return false if target_path.exist?
+
+      target_path.dirname.mkpath
+      before_transcode&.call
+
+      audio.transcode(target_path.to_s, target_sample_rate: target_sample_rate,
+                                        target_file_type: target_file_type,
+                                        target_bit_depth: target_bit_depth || source_bit_depth)
+
+      true
+    end
+  end
+end
diff --git a/lib/wavesync/scanner.rb b/lib/wavesync/scanner.rb
index 5a487ea..0d2893a 100644
--- a/lib/wavesync/scanner.rb
+++ b/lib/wavesync/scanner.rb
@@ -2,6 +2,7 @@
 
 require 'fileutils'
 require 'streamio-ffmpeg'
+require_relative 'file_converter'
 
 module Wavesync
   class Scanner
@@ -9,6 +10,7 @@ def initialize(source_library_path)
       @source_library_path = File.expand_path(source_library_path)
       @audio_files = find_audio_files
       @ui = Wavesync::UI.new
+      @converter = FileConverter.new
       FFMPEG.logger = Logger.new(File::NULL)
     end
 
@@ -31,8 +33,12 @@ def sync(target_library_path, device)
         @ui.file_progress(file)
 
         if file_type || target_sample_rate || target_bit_depth
-          converted = convert_file(audio, file, path_resolver, file_type, source_sample_rate,
-                                   target_sample_rate, source_bit_depth, target_bit_depth)
+          converted = @converter.convert(audio, file, path_resolver, file_type, source_sample_rate,
+                                         target_sample_rate, source_bit_depth, target_bit_depth) do
+            source_file_type = File.extname(file).delete_prefix('.')
+            @ui.conversion_progress(source_sample_rate, target_sample_rate, source_bit_depth,
+                                    source_file_type, file_type, target_bit_depth)
+          end
           target_path = path_resolver.resolve(file, audio, target_file_type: file_type)
         else
           copied = copy_file(audio, file, path_resolver)
@@ -84,28 +90,5 @@ def safe_copy(source, target)
     rescue Errno::ENOENT
       puts 'Errno::ENOENT'
     end
-
-    def convert_file(audio, source_file_path, path_resolver, target_file_type, source_sample_rate,
-                     target_sample_rate, source_bit_depth, target_bit_depth)
-      return false unless target_file_type || target_sample_rate || target_bit_depth
-
-      target_path = path_resolver.resolve(source_file_path, audio, target_file_type: target_file_type)
-
-      files_to_cleanup = path_resolver.find_files_to_cleanup(target_path, audio)
-      files_to_cleanup.each { |file| FileUtils.rm_f(file) }
-
-      return false if target_path.exist?
-
-      target_path.dirname.mkpath
-      source_file_type = File.extname(source_file_path).delete_prefix('.')
-      @ui.conversion_progress(source_sample_rate, target_sample_rate, source_bit_depth, source_file_type,
-                              target_file_type, target_bit_depth)
-
-      audio.transcode(target_path.to_s, target_sample_rate: target_sample_rate,
-                                        target_file_type: target_file_type,
-                                        target_bit_depth: target_bit_depth || source_bit_depth)
-
-      true
-    end
   end
 end
diff --git a/test/wavesync/file_converter_test.rb b/test/wavesync/file_converter_test.rb
new file mode 100644
index 0000000..d1ad29c
--- /dev/null
+++ b/test/wavesync/file_converter_test.rb
@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+require_relative 'test_case'
+require_relative '../../lib/wavesync/file_converter'
+require_relative '../../lib/wavesync/path_resolver'
+require_relative '../../lib/wavesync/device'
+
+module Wavesync
+  class FileConverterTest < Wavesync::TestCase
+    def setup
+      @source_dir = Dir.mktmpdir
+      @target_dir = Dir.mktmpdir
+      @device = Device.find_by(name: 'TP-7')
+
+      @converter = FileConverter.new
+      @path_resolver = PathResolver.new(@source_dir, @target_dir, @device)
+    end
+
+    def teardown
+      FileUtils.rm_rf(@source_dir)
+      FileUtils.rm_rf(@target_dir)
+    end
+
+    test 'convert skips when converted file already exists in source location' do
+      source_aiff = File.join(@source_dir, 'track.aiff')
+      FileUtils.touch(source_aiff)
+      FileUtils.touch(File.join(@source_dir, 'track.mp3'))
+
+      audio = stub(bpm: nil)
+      result = @converter.convert(audio, source_aiff, @path_resolver, 'mp3', 44_100, nil, 16, nil)
+
+      assert_equal false, result
+    end
+
+    test 'convert does not skip when converted file does not exist in source location' do
+      source_aiff = File.join(@source_dir, 'track.aiff')
+      FileUtils.touch(source_aiff)
+
+      audio = stub(bpm: nil)
+      audio.stubs(:transcode)
+
+      result = @converter.convert(audio, source_aiff, @path_resolver, 'mp3', 44_100, nil, 16, nil)
+
+      assert_equal true, result
+    end
+
+    test 'convert skips when converted file already exists in target location' do
+      source_aiff = File.join(@source_dir, 'track.aiff')
+      FileUtils.touch(source_aiff)
+      FileUtils.touch(File.join(@target_dir, 'track.mp3'))
+
+      audio = stub(bpm: nil)
+      result = @converter.convert(audio, source_aiff, @path_resolver, 'mp3', 44_100, nil, 16, nil)
+
+      assert_equal false, result
+    end
+  end
+end