One of the most annoying parts of the web is auto-playing videos and ads. Google Chrome, Microsoft Edge, and other browsers introduced new mechanisms over the last year that automatically blocks out these auto-playing media, and Firefox is finally joining in.
Starting with Firefox 66, the browser will automatically start blocking automatically playing audio and video. There is a slight annoyance, however — instead of completely blocking the playback, Firefox will simply mute whatever is auto-playing audio. This means if a site has auto-playing video, it will still eat up your data, which could be problematic if you are on a limited data plan or using mobile hotspot.
Firefox will also let users manually allow auto-playing sound on certain sites if they want to.
The company has outlined the technical details about the feature for web developers here. It plans to start rolling out the feature with Firefox 66 on March 19 across all platforms.