Why sound is muted by default when a video is set to autoplay in a website's top header

If you add a video to one of your single property websites and select it to autoplay in the top header the sound will be muted by default. The user needs to click the sound icon at the bottom of the video to turn the sound on if they'd like to hear it. We do this to avoid having the video blocked entirely.

Here's the background on why:

The major web browsers currently enforce videos to be muted when set to autoplay on page load. If not, they may block the video and prevent it from being watched at all.

In order to ensure your video autoplays across all modern browsers, we have added the "muted" attribute to the video tag and then provide a user control to unmute if desired.

For Chrome, muted autoplay is always allowed but videos with sound are blocked by default unless certain conditions are met (such as user interaction with the site or if the user has previously engaged with media on that site).

Firefox applies autoplay blocking to any media with an active audio track. However, autoplay blocking is not applied to video elements when the source media doesn't have an audio track or if the audio track is muted.

Safari, by default, allows muted players to start automatically but blocks nearly all auto-playing media with sound with sound on by default.

For Microsoft Edge, some versions do not have native capabilities to prevent HTML5 videos from playing automatically if they have sound but current and future versions will.