YouTube is testing new player built with HTML5 instead of Flashplayer.
HTML5 player uses less system resources, video streaming is better too. I recommend switching to HTML5 player.
HTML5 player is supported with following browsers:
- Firefox 4
- Google Chrome
- Opera 10.6+
- Apple Safari (h.264, version 4+)
- Microsoft Internet Explorer 9
- Microsoft Internet Explorer 6, 7 or 8 with Google Chrome Frame installed (Get Google Chrome Frame)
- Videos with ads are not supported (they will play in the Flash player)
- On Firefox and Opera, only videos with WebM transcodes will play in HTML5
- If you've opted in to other testtube experiments, you may not get the HTML5 player (Feather version of YouTube is supported)
For more compatibility tests about your browser visit youtube.com/html5 and see the section What does my browser support?
You can join HTML5 YouTube Player trial by visiting youtube.com/html5 and click Join the HTML5 trial at the end of the page.