When this article was first written in early 2013 none of the major web browsers supported all the features of the HTML video tag. See also the Video for Everybody article for more information on supporting video playback using HTML on a web page.
width) to prevent the bars from appearing. If necessary just resize in one dimension (e.g. Note that videos retain their aspect ratio and if the new width and height do not respect that aspect ratio then dark bars will appear on either side of the video. The width and height attributes (in pixels) on the video tag can be used to resize a video. Note that this is an example of the video tag that contains multiple source tags so that a browser can choose the best format that it supports:
The above is equivalent to the following example HTML code. A browser will show a placeholder for the video and the video controls, the video should play when started. In the video that follows preload has been set to none. Note that preload is a hint to the browser, so browsers may ignore this setting.
If you can see the start of this MP4 format waterfall video, and can play it, then your browser supports MPEG video playback (.mp4): The following 8 tests look at different aspects of the video tag.
The recent versions of the most popular browsers (Internet Explorer, Chrome, Firefox, Safari, Edge and Opera) all support the HTML5 video tag. You will also be able to determine whether your browser supports one, two or all three of the common formats, and whether those three formats can all appear in the same video tag.
If your browser, software or device supports the video tag that was introduced with HTML5 then you will be able to play one of the video formats. Check Browser Support for the HTML Video Tag The video is in the three common web formats MPEG (.mp4), WebM (.webm), OGG (.ogv). In this article there is a short test video for HTML5.