Conformance Demo for WCAG 2.1 Success Criterion 1.2.1 Audio-only and Video-only (Prerecorded) (Level A)

1.2.1 Conformance Shown with Non-Technical Explanation

Note Applicable to all Examples

All of the examples on this page except one use the accessibility friendly Able Player. It is deliberately offset to the left to permit the transcript to be viewable to the right of the player.

Conformance Example 1

The first video has an embedded audio description track.

Conformance Example 2

The second video has a timed text audio description track the can be read by user agents such as screen readers. If your browser supports the Web Speech API, the browser will read it when the video is playing and the track is toggled on without the aid of a screen reader.

Conformance Example 3

The third video wraps the Able Player around an embedded YouTube video.

Conformance Example 4

Viewers might be watching your videos on YouTube. As seen in success example 1, one can upload an alternate version of the video with an embedded audio description track. In other instances, it may be possible to provide adequate description in the description box or provide a link to a transcript. The fourth example is the video as it appears on YouTube.

1.2.1 Conformance HTML Markup with Technical Details

Each HTML5 video element has a <video> start tag and a </video> end tag. The track tag that contains the audio description or caption file is inside the video element, in between the starting and ending video tags. The markup for examples 2 and 3 above:

<track src="121captions.vtt" kind="captions" label="English">
<track src="121descriptions.vtt" kind="descriptions" label="English">

Each track tag has a required src attribute that specifies the path to the source file. A valid source file for the track tag must be in the Web Video Text Tracks format. WebVTT files use a .vtt file extension. The value for track src will always end in .vtt. The kind attribute values are where one can distinguish between captions and (audio) descriptions. The label attribute is not required, but useful if you don't want to use a language code abbreviation to label the track language for the player. Able Player doesn't seem to support the label attribute.

YouTube videos don't use the HTML5 track tags even on video pages marked up in HTML5, at least not in a way visible to the end user.