Perceivable · 1.2 Time-based Media
Prerecorded video with sound must include sign language interpretation of all of its audio content, usually as an interpreter shown alongside the video or as a separate signed version.
Live demo
The same task, done two ways: switch between the version that passes and the one that fails, or put them side by side. Everything in the box is live, so try it with a keyboard, a pointer or a screen reader.
Play the video. Passes shows a sign language interpreter next to the presenter; Fails has captions only.
A short announcement from your bank.
A short announcement from your bank.
The tools follow the version you last used.
What happened
Why it passes
An interpreter signs everything that is said, next to the presenter. A Deaf viewer whose first language is a sign language follows it in that language.
Why it fails
Only captions are offered. For many Deaf viewers written English is a second language, so the captions are harder to follow than signing.
Examples
Four examples, each one running: the usual ways this criterion fails, and code that passes. Listen to them, measure them, or copy the code.
Fails
Live preview
<video controls src="/video/opening-hours.mp4"> <track kind="captions" src="/video/opening-hours.en.vtt" srclang="en" label="English" default></video>Captions meet 1.2.2, but at level AAA the speech must also be interpreted in a sign language.
Passes
Live preview
<video controls src="/video/opening-hours-bsl.mp4"> <track kind="captions" src="/video/opening-hours.en.vtt" srclang="en" label="English" default></video><p>This version includes a British Sign Language interpreter.</p><p><a href="/video/opening-hours.mp4">Watch without the interpreter</a></p>The interpreter is part of the picture, so the signing stays in step with the speech. A link offers the version without the interpreter.
Fails
Live preview
.player { position: relative; }.player .sign-video { position: absolute; right: 8px; bottom: 8px; width: 10%;}At a tenth of the player's width, the interpreter's hands and face are too small to read, especially on a phone.
Passes
Live preview
.player { display: grid; grid-template-columns: 2fr 1fr; gap: 8px;}.player .sign-video { width: 100%; height: 100%; object-fit: cover;}The interpreter gets a third of the player's width next to the programme, so hand shapes and facial expressions stay clear and nothing is covered.
Why it matters
Many Deaf people whose first language is a sign language understand signed content more fully than written captions, which are in a second language for them.
W3C: Understanding 1.2.6Level AAA
Level AAA is the highest level. It is not required for whole sites, but it is worth meeting where you can.
Where it is required
No law on this site requires Level AAA criteria for whole sites.
How to test
A few concrete steps. Automated tools find some failures; most need a person.
Common failures