WCAG 1.2.3 Audio Description or Media Alternative (Prerecorded)

Success criterion 1.2.3 makes sure that people who are blind or have low vision get the visual information in a recorded video: what is shown, demonstrated or written on screen. It is level A and part of EN 301 549 (clause 9.1.2.3).

What the criterion requires

For prerecorded synchronized media (video with sound), provide one of the following:

• Audio description of the video content — narration that describes important visual details, usually fitted into natural pauses in the dialogue; or
• an alternative for time-based media — a document that presents, in the correct order, both the audio and the visual content (a "descriptive transcript"), with a way to reach the same results as any interactive parts of the media.

Exception: the video is a media alternative for text that is already on the page and is clearly labelled as such.

If all important visual information is already in the audio track, no additional audio description is necessary.

At level AA, 1.2.5 narrows the choice: audio description is then required, and the text alternative alone is no longer enough.

Typical failures on an online shop

• a product video where the presenter says "just do this" and the step is only shown;
• on-screen text such as sizes, prices or a discount code that nobody reads aloud;
• a brand video with music only and visual storytelling, with no description at all;
• a transcript that contains the speech but leaves out what happens on screen.

How to check it

Automated: no automated rule in our checker maps to this criterion. Whether visual information is missing from the audio can only be judged by watching. This needs a manual check.

By hand: watch each video, then listen to it with the screen off. Write down anything you missed — actions, text, product details. Then check that an audio-described version or a descriptive transcript covers each of those points, in order.

How to fix it

• Plan videos so the narrator says what is shown: "Pull the tab on the left side until it clicks".
• Read out any on-screen text that matters.
• Publish a descriptive transcript next to the video: speech plus bracketed descriptions of the action.
• For important videos, record an audio-described version and offer it as a separate track or file.

Related criteria

• 1.2.5 Audio Description (Prerecorded) — audio description at level AA.
• 1.2.2 Captions (Prerecorded) — the audio track for deaf users.
• 1.2.1 Audio-only and Video-only (Prerecorded) — recordings with only sound or only picture.

Frequently asked questions

Is a transcript enough for 1.2.3?

A plain transcript of the speech is not enough. The text alternative must describe both what is said and what is shown, in the right order. A descriptive transcript like that meets 1.2.3; at level AA, 1.2.5 still asks for audio description.

When is no audio description needed?

When all important information in the picture is already conveyed by the audio — for example a talking-head video where the speaker says everything and nothing important is only shown.

What is audio description?

Narration added to the soundtrack that describes important visual details — actions, on-screen text, scene changes — usually placed in natural pauses in the dialogue.