Check if the website supports html5.
Want to know if the page you are viewing supports html5.
simply install this extension and when the page loads a small notifications displays whether the page support html5.
A HTML5 video speeder
ニコニコ動画に再生/停止, 巻き戻し, 早送り, コメント入力, その他便利なショートカットキーを追加します
Disables autoplay of all HTML5 audio and video
A11Y HTML5 Validator
Can you change of Speed(0.07-16x)/Loop/Rotate for HTML5 Video(Mouseover/Hold/ContextMenu/DoubleClick).
Disables autoplay of all HTML5 audio and video
本扩展基于 flv.js ,用于将直播的 Flash 播放器替换为 html5 播放器。
A handy reference of HTML5.
HTML5 Player for Subsonic & Archive.org
为Acfun替换一个和官方Flash播放器界面高度相仿的HTML5播放器。