Create text with several medias in it: .mp4, .flv, .mp3, .wav ; insert a link to youtube video Create text with <video> that has tracks (subtitles, cc, chapters, etc) Make sure video.js player is enabled and has priority (site administration > plugins > media players); enable youtube and flash in video.js settings View the text with medias in several browsers (including mobile), make sure they are displayed/played well and are responsive; make sure you can choose subtitles Change the language to something non-english (supported by video.js, see list ), make sure the buttons labels in the player are translated (note, not all languages have all translations)