How can youtube autoplay video with audio on Safari?

Question

As far as I know, HTML5 only autoplay when muted on safari.

However, youtube was able to autoplay video with audio.

Did youtube get exception from Safari?

How did they make it happen?

For example, if you go to https://www.youtube.com/watch?v=5dpIPeTgA64, the video will autoplay with audio.

Thanks.

Answer 1

by default, safari whitelists youtube to allow autoplay. if you open youtube.com and examine preferences/websites you'll see youtube listed.