Success Criteria

WCAG 1.2.3 Audio Description or Media Alternative (Prerecorded)

Success Criterion 1.2.3 requires either an audio description track or a full text/media alternative for prerecorded video content, covering visual information that isn't already conveyed through the existing dialogue or audio. It's a Level A criterion under Guideline 1.2 (Time-based Media).

The gap this closes

Captions (1.2.2) solve the problem of hearing what's said. This criterion solves a different problem: a lot of video communicates through what's shown, not said — an on-screen chart appearing silently, a character's action or expression, text displayed briefly on screen. A blind viewer listening to the audio track alone misses all of that unless it's independently described.

Two ways to satisfy it

Audio description — a narration track (either a separate track or, for videos with enough natural pauses, inserted into gaps in the existing dialogue) that describes the important visual content as it happens.

A full media alternative — a complete text document describing everything in the video, both audio and visual, timed or referenced well enough to serve as a substitute for watching it. This is a heavier-weight alternative, more commonly used when adding an audio-description track isn't practical.

When this doesn't apply

If a video's visual content adds nothing beyond what the audio/dialogue already conveys — a talking-head interview with no supporting visuals, for instance — there's often no additional visual information that needs describing, and the criterion may already be satisfied by the existing audio alone. The test is whether a blind listener, hearing only the audio, would miss anything meaningful that a sighted viewer perceives.

Its stricter AA sibling

WCAG 1.2.5 (Level AA) requires audio description specifically (not the lighter "or media alternative" option) for all prerecorded video — meaning at AA conformance, the media-alternative-document option from 1.2.3 is no longer sufficient on its own for video with meaningful visual content; a real audio-description track becomes the expected implementation.

Common questions

What is WCAG 1.2.3?

A Level A criterion for prerecorded synchronized media, satisfied by providing either audio description of the visuals or a full text media alternative for the video.

How is 1.2.3 different from 1.2.5?

1.2.3 (Level A) accepts either audio description or a text alternative; 1.2.5 (Level AA) requires audio description specifically.

Does a plain transcript satisfy 1.2.3?

Yes, if it is a full text alternative covering both the spoken dialogue and the important visual information, not just the audio track.