YouTube now offers an option to play video natively within supported browsers using HTML5 rather than the Adobe Flash plug-in. It is only an experiment, and it did not work when informitv tried it, but is a significant sign of support for the HTML5 standard, with implications for network connected television devices and displays.

HTML5 is the latest working draft of the standard markup language, including support for <audio> and <video> playback without requiring a browser plugin. However, it is only supported by certain browsers and does not standardise the format or compression scheme of the video.

The YouTube HTML5 beta works with the Google Chrome browser and later versions of Apple Safari, as well as Microsoft Internet Explorer with Chrome Frame installed. It also has significant limitations, including the inability to play back full screen video, captions or annotations. It does not currently support advertisements, which may not such be a problem for users.

YouTube, owned by Google, is pushing the Google Chrome browser, which is also being heavily promoted through advertising campaigns. Chrome currently has around 5% of the browser market, about the same as Safari. Both use the WebKit layout engine.

The YouTube HTML5 experiment pragmatically uses H.264 encoded video, as supported by Flash. This has disappointed proponents of Theora, an open video compression format which does not require licence fees.

The support for native H.264 video playback from Google and YouTube is still significant. Flash will continue to be used to reach the vast majority of web users and support more sophisticated features, but is no longer required for other devices that could offer access to YouTube. It could also encourage other online video services to consider native support for video using HTML5.