How to: Trick websites to serve HTML5 video
Flash is about the only thing that crashes Safari. Further if you’re using a laptop — Mac, Windows, whatever — Flash content churning somewhere in the background can eat up to 33 percent of the available battery uptime. However, you can get many sites to play mobile H.264 web video without Adobe’s middleware installed.
The real irritant with Flash video is that the great majority of it is also available in HTML5 (H.264) format, but only to folks running browsers that identify them as using a mobile device. Here’s a simple way to get around that technicality.
This work around is only valid if you’re running without Flash installed. In my limited testing, with Flash and/or a Flash blocker installed, such as ClickToFlash, sites won’t load the HTML5 version.
If it’s not already active, turn on Safari’s “Develop” menu (Preferences > Advanced > Click the checkbox). Now, whenever you come across a video that says it requires Flash, just go to the Develop menu and choose Mobile Safari 3.2.2 under User Agent.
Changing User Agents should cause the offending page to reload and, if HTML5 video is available, it will be displayed. To take this little trick one step further, assign a keyboard shortcut and you can learn all about that here.
An imperfect world
Nevertheless, hats off to DaringFireball for connecting the dots…