Mounir Lamouri, a software engineer at Google, posting on the Google Chromium blog:
Starting in Chrome 64, autoplay will be allowed when either the media won’t play sound, or the user has indicated an interest in the media. This will allow autoplay to occur when users want media to play, and respect users’ wishes when they don’t. These changes will also unify desktop and mobile web behavior, making web media development more predictable across platforms and browsers.
Not all users have the same preferences for autoplay media, so Chrome 63 will add a new user option to completely disable audio for individual sites. This site muting option will persist between browsing sessions, allowing users to customize when and where audio will play.
Autoplay video is a bane of the web right now. Advertisers love it, users hate it. I honestly cannot think of a more user-hostile experience out there. Safari in High Sierra will block autoplay video, so it’s good to see Google jumping on the bandwagon. Sorry, advertisers—bottom’s about to fall out of this market, and none too soon.