Question

I am trying to develop a simple webpage with all the newly added basic elements of html5. While working with the video tag, I see that some formats like .avi are not supported.

So is there a list of video formats supported by html5?

Even if a particular format like WebM/ogg is supported by html5, is it safe enough to presume that the browser used will be capable to display the video?

Answer 1

There is no universally supported format (yet) unfortunately. Technically, HTML5 doesn’t support any video formats, it’s the browsers themselves that support specific video formats. This has led to a giant mess.

You can find a list of format compatibility on Wikipedia. From that, VP8/WebM is likely your best bet if you only want to support a single format. Luckily the <video> tag does support fallbacks if providing more than one encoding is feasible for your uses, in which case a VP8/WebM version combined with a H.264 version covers every major browser.

For multiple versions of the same video, you can use the following code:

<video width="320" height="240">
  <source src="myvideo.mp4" type="video/mp4" />
  <source src="myvideo.ogv" type="video/ogg" />
  <source src="myvideo.webm" type="video/webm" />
  <p>Other backup content, eg. a flash version, should go here.</p>
</video>