According to AndroidCentral, some users are seeing the first video featured in the Home section automatically play as soon as they open the YouTube app, with subtitles replacing the muted audio.
The video starts from the beginning and plays all the way through if the user allows it, while scrolling further down the Home section causes subsequent videos to also autoplay as they appear on the screen.
While the default behavior is obviously intended to give users a preview of the contents of featured videos, the experimental feature is likely to be seen by some as a distraction, bad news for mobile data limits, or a drain on battery life.
Fortunately, it looks like the autoplay feature can be turned off in Account -> Settings -> General, where a new “Play as you browse” toggle has been added. Toggling the feature also brings up an additional option to only allow autoplay when connected to WiFi, which should go some way to assuage concerns about the feature eating up data allowances.
It’s not clear if or when the autoplay feature will be rolled out to all mobile users, but we’ll keep an eye out for it in future updates to the official YouTube iOS app.