Mozilla has enabled AV1 video support by default in Firefox 66 Nightly on Windows by flipping media.av1.enabled to true. Vivaldi and Chrome already support AV1, sometime back, Microsoft has released an extension to add support for Windows 10 available on the store for the same, now Firefox maker did that for its browser to join the list.
Before that, you might want to read, how to play AV1 videos on YouTube, Firefox, Chrome, Opera and Vivaldi browsers.
To test the feature right away in Firefox browser
1. Ensure you’re using latest Firefox Nightly on Windows and visit Youtube/testtube page
2. Select either ‘Prefer AV1 for SD’ or ‘Always prefer AV1’
3. Visit AV1 Beta Playlist link in YouTube and play a video, while the video is playing, right click on it and select ‘Stats for nerds’ to notice videos being played with Av1 codec, the line av01.0. displayed for Codecs confirms that.
Are you excited about this development?