Rampsight

All rules

Text alternatives

Video needs captions

Why it matters

Without captions, everything spoken in the video is unavailable to anyone deaf or hard of hearing — and to the much larger group watching with the sound off.

How to fix it

  1. Add a <track kind="captions"> file to the <video> element.
  2. Caption the meaningful sounds as well as the speech.
  3. Publish a transcript underneath for anyone who would rather read than watch.

In markup

Fails
<video src="tour.mp4" controls></video>
Passes
<video src="tour.mp4" controls>
  <track kind="captions" src="tour.vtt" srclang="en" label="English">
</video>

What the check cannot tell you

The check sees whether a captions track is declared. Auto-generated captions full of errors pass it and still fail the viewer.

The requirement behind it

This rule is one way of failing the following WCAG 2.2 success criteria. The W3C, which writes the standard, explains each of them:

Further reading

Deque University on video-caption (opens in new tab)

Deque maintains axe-core, the open-source engine our scanner runs. Their page documents the rule as the engine implements it.

Automated checks find failures a browser can prove. They cannot judge whether a caption is accurate, whether an alt text is useful, or whether a page can be operated end to end with a keyboard — those need a person.