Yes, I switched to Firefox! In the matter of fact that happened two or three months ago, but I’ll not talk about that right now because that’s an article on its own. Instead of that this article will focus on how to enable HTML5 HD video playback on Youtube.

If you tried using Firefox without Flash, and watching videos on YouTube just with built-in HTML5 video capabilities of your browser you probably noticed that video resolution is limited to 360p, and frankly, that sucks. So lets fix it!

Firstly, visit Youtube HTML5 Video Player page and check what does your browser support. According to that we’ll change few options in your about:config page.

To have all those options available you’ll need to make sure the following options are set to true:

media.mediasource.enabled
media.mediasource.webm.enabled
media.fragmented-mp4.exposed
media.fragmented-mp4.ffmpeg.enabled

Then go back to Youtube HTML5 Video Player page and check if all options are available now.

Hopefully that should enable you to set higher resolutions while watching YouTube videos.