Audio and video
Audio needs captions or a transcript
- Rule:
audio-caption - Severity: Critical
- WCAG level A
Why it matters
Recorded speech is inaccessible to anyone deaf or hard of hearing, and to everyone in a noisy place or without headphones. Nothing on the page conveys what was said.
How to fix it
- Add a <track kind="captions"> file to the <audio> element.
- Publish a text transcript next to the player as well — it is also what a search engine reads.
- Include the speaker names and any meaningful non-speech sound.
In markup
<audio controls src="interview.mp3"></audio><audio controls src="interview.mp3">
<track kind="captions" src="interview.vtt" srclang="en" label="English">
</audio>What the check cannot tell you
The check sees whether a captions track exists, not whether it is accurate or synchronised. A wrong transcript passes.
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 audio-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.