Although Google Chrome browser uses HTML5 player on YouTube website to play videos whenever possible, but this is not the case with Firefox, default player currently supports HTMLVideoElement, H.264, WebM VP8 and good news for fire Fox users using Nightly build which is currently at version 32 is compatible with Media source extensions for HMTL5 player is hidden behind a preference that you can enable and enjoy better youtube playerhere’s how to do it.
Enabling Media Source Extensions in Firefox
1. Visit about:config
2. Double-click “media.mediasource.enabled” preference to turn to true.
Now when you visit YouTube.com/html5 in Firefox you can see the default player which supports all except MSE and H.264.