Back in December, Google was testing out the ability to mute autoplaying videos on its Chrome browser. Now in Google Chrome 66 version, this feature goes live for users on both the desktop and mobile apps. Chrome will now automatically block these videos from autoplaying. As for those that are set to autoplay without sound, those will continue to play in the background. Another exception is for sites where you have “previously shown an interest in media on the site.” So, if you use YouTube a lot, expect autoplaying videos from there to start playing.
Source: Mashable