In order to avoid erecting a paywall, webmasters who want to keep their content 'free' must walk a fine line between delivering ads to pay the bills (and writers), and not overwhelming readers, who might be tempted to enable an ad blocker. In a sense, browser makers also have a balancing act on their hands. One thing they seem to agree on, though, is that autoplaying audible video and audio is undesirable, and so Mozilla is planning to crack down on this with Firefox 66.
"We know that unsolicited volume can be a great source of distraction and frustration for users of the web. So we are making changes to how Firefox handles playing media with sound. We want to make sure web developers are aware of this new autoplay blocking feature in Firefox," Mozilla stated in a blog post. "Starting with the release of Firefox 66 for desktop and Firefox for Android, Firefox will block audible audio and video by default."
Once Firefox 66 rolls out, sites will only be allowed to automatically play audio or audible videos using the HTMLMediaElement API, once a user has interacted with the site in a way that would enable it, such as clicking on a 'Play' button.
"Any playback that happens before the user has interacted with a page via a mouse click, printable key press, or touch event, is deemed to be autoplay and will be blocked if it is potentially audible," Mozilla added.
This will be the default setting in Firefox 66, which is scheduled for general release on March 19, 2019. In Firefox for Android, this mechanism will replace the existing autoplay blocking implementation so that it acts the same as it does on the desktop.
If a user encounters a site where autoplaying audio and video with sound is desirable, they can enable it by clicking on an icon in the URL bar, which will bring up an information panel. There will be a pull-down menu in there to manually change the default setting from Block to Allow. This basically allows a user to create a whitelist, on a site-by-site basis.
Ahead of the change, Mozilla's advice to web developers is that if they want to avoid having their audible playback blocked in the near future, they should tuck audible media inside a click or keyboard event handler (or in a touchend event on mobile). Alternately, they can autoplay videos with the sound muted, and present users with an unmute button.
"We are also allowing sites to autoplay audibly if the user has previously granted them camera/microphone permission, so that sites which have explicit user permission to run WebRTC should continue to work as they do today," Mozilla said.
This is good news for Firefox users. It's also a feature that is a long overdue—Chrome, Edge, and Safari all implemented similar autoplay restrictions a long time ago.