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Technique F93:Failure of Success Criterion 1.4.2 for absence of a way to pause or stop an HTML5 media element that autoplays

About this Technique

This technique relates to 1.4.2: Audio Control (Failure).

This failure applies to HTML.

Description

This failure occurs when an audio or video element with an audio track contains the autoplay attribute and does not contain the muted attribute, and no controls or commands have been provided to pause or stop the media resource.

When the autoplay attribute is present, the user agent will automatically begin playback of the media resource as soon as it can do so without stopping. When the muted attribute is present, the user agent will initially mute the media resource's audio output, overriding any user preference.

If the media element is shorter than 3 seconds, the failure does not occur. If the user agent provides user preferences to override autoplay behavior, the failure does not occur.

The HTML spec contains the following notes:

  • User agents do not need to support autoplay, and it is suggested that user agents honor user preferences on the matter. Authors are urged to use the autoplay attribute rather than using script to force the video to play, so as to allow the user to override the behavior if so desired.
  • 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. 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.

Examples

Example 1: An auto-playing audio track

In this example, the advertising video contains an audio track. The video will play continuously because of the loop attribute, and the video will start automatically because of the autoplay attribute and because there does not appear to be any controls to allow the user to stop the video.

<video src="ads.cgi?kind=video" autoplay loop></video>

Related Resources

No endorsement implied.

Tests

Procedure

  1. Check if an audio or video element has an active audio track.
  2. Check if the audio or video lasts longer than 3 seconds.
  3. Check if the element has an autoplay attribute.
  4. Check if the element does not have a muted attribute.
  5. Check if no command or control has been provided to stop or pause the media element.

Expected Results

  • If checks #1-5 are true, then this failure condition applies and the content fails the Success Criterion.
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