Just over three years ago I wrote an article called Autoplay is bad for all users. It was written a few months after WCAG 2 became a formal recommendation but before HTML5, particular the
video element, had really gone into mass production.
Much, if not all, of that article still holds true today but there are a couple of points to add to it.
The new HTML5 specification includes the
autoplay attribute along with the following provisions:
Authors are urged to use the autoplay attribute rather than using script to trigger automatic playback, as this allows the user to override the automatic playback when it is not desired, e.g. when using a screen reader.
This is the one advantage to
autoplay being included in the spec. If authors must automatically play video this provides a relatively easy way for the user to disable that functionality.
Authors are also encouraged to consider not using the automatic playback behavior at all, and instead to let the user agent wait for the user to start playback explicitly.
This is great! However, in the spec it isn’t a separate guideline so I don’t imagine it will be seen by the majority.
Apple and autoplay
Apple has made the decision to disable the automatic playing of video on iOS devices, through both script and attribute implementations:
In Safari on iOS (for all devices, including iPad), where the user may be on a cellular network and be charged per data unit, preload and autoplay are disabled. No data is loaded until the user initiates it.
…autoplay is disabled to prevent unsolicited cellular download.
Autoplay on mobile devices
Apple aren’t the only company to make the decision to disable automatic playing of video, as far as I can tell, all of the most modern mobile devices ignore the
autoplay attribute which can only be a step in the right direction for accessibility.
To summarise, I’ll repeat the conclusion from my previous post:
- Only automatically play video if the clip lasts for five seconds or fewer (‘Five seconds’ relates to the timing mentioned in the success criterion for Moving, blinking, scrolling).
- If the clip lasts for more than five seconds, you must provide the user with the option to stop or pause it.
- Automatic playback is generally acceptable if the user was aware, when they clicked the link, that the proceeding page was going to play a clip.