WCAG 1.2.3: Audio Description or Media Alternative (Prerecorded)
A video’s soundtrack rarely tells the whole story. Actions, gestures, scene changes, and on-screen text all carry meaning that a blind viewer never receives. This criterion asks that, for prerecorded video with audio, the important visual information is conveyed either through an audio description or through a full text alternative. Get it right and the story that plays out on screen becomes available to people who can only listen or read.
The success criterion, in full
An alternative for time-based media or audio description of the prerecorded video content is provided for synchronized media, except when the media is a media alternative for text and is clearly labeled as such.
“Synchronized media” means video with a soundtrack — the audio and moving pictures play together. The criterion covers only the visual information (captions handle the audio for deaf users under 1.2.2). You may satisfy it two ways: describe the visuals in an audio track, or provide a complete text alternative for the whole video. The one carve-out is when the video merely re-presents information already available in text and says so clearly.
Who this helps
The primary audience is people who cannot see the screen, but describing visual content clearly benefits far more people than that:
Blind users
The core audience. Without description, everything that is shown but not spoken — actions, settings, gestures, on-screen text — is simply missing from the experience.
Low vision users
People using magnification or high contrast may not make out facial expressions, small on-screen text, or fine detail; a description fills those gaps.
People who look away or multitask
Anyone watching while cooking, driving, or working can keep up through the audio alone when the visuals are described.
People with cognitive and learning disabilities
Explicit, spoken descriptions of what is happening reduce the effort of interpreting busy or fast-moving visuals and reinforce understanding.
Learners and second-language users
A clear verbal account of the visual content, or a readable text alternative, supports comprehension and lets people study at their own pace.
Users on limited bandwidth
When streaming is difficult, a text media alternative offers a lightweight way to get the full content without loading the video at all.
What the requirement covers
1.2.3 applies to prerecorded synchronized media — video that has a soundtrack. It is concerned only with the information carried by the picture, because the audio track is already handled by captions under 1.2.2 Captions. You can meet it in one of two ways:
(a) Audio description
A narration track that describes the important visual information during the natural pauses in dialogue and sound. It rides alongside the original audio and can typically be switched on or off. This is the route required at Level AA by 1.2.5.
(b) Full text media alternative
A standalone document that describes both the visual and the auditory content of the video in the correct order — all dialogue and narration plus every meaningful action, scene, and on-screen text. A reader gets the complete experience without watching.
What counts as important visual information
The test for what to describe is whether the information is needed to understand the content and is not already conveyed by the existing audio. In practice that means:
- Actions and events. What people and objects do on screen — someone signs a document, a chart animates, a product is assembled.
- Characters and who is present. Who appears, how they look when it matters, and meaningful expressions or gestures that are not spoken aloud.
- Scene and setting changes. Where the action takes place and when it moves — a cut to a new location, a jump in time, a change of context.
- On-screen text and graphics. Titles, captions burned into the picture, slides, diagrams, and any text or data shown visually but never read out.
The exception, briefly
If the video exists only as an alternative to text that is already on the page — and it is clearly labeled as such — 1.2.3 does not apply, because the equivalent information is already fully available in that text. Everywhere else, if there are no natural pauses long enough for description, provide the full text media alternative; pausing the video for longer descriptions is the AAA-level 1.2.7 Extended Audio Description, not a requirement here.
Pass and fail examples
✓ Passes 1.2.3
- A tutorial video offering a selectable audio description track that narrates on-screen steps during the pauses.
- A product demo linked to a full text alternative describing every action, scene, and spoken line.
- A drama with descriptions of who enters a room and what they do, inserted between lines of dialogue.
- A video that simply re-presents an article, clearly labeled as an alternative to that text (exception applies).
✗ Fails 1.2.3
- A video where key actions happen silently on screen, with no description and no text alternative.
- On-screen text or data (prices, results, code) that is never spoken and never described.
- Captions provided but no audio description — captions serve deaf users, not blind users.
- A transcript that lists only the dialogue and omits all the visual content of the video.
Code examples
Dialogue only, nothing described (fail)
A plain video with no description track and no linked alternative leaves all of its visual meaning inaccessible.
<!-- ✗ Visual content is never described or offered as text -->
<video controls width="600">
<source src="tutorial.mp4" type="video/mp4">
<track kind="captions" src="captions.vtt" srclang="en" label="English">
</video>An audio-described track (pass)
Add a <track kind="descriptions"> pointing at a WebVTT file whose cues describe the visuals in the pauses. (Player support varies, so many teams also offer a separately described video source.)
<!-- ✓ Description track added alongside captions -->
<video controls width="600">
<source src="tutorial.mp4" type="video/mp4">
<track kind="captions" src="captions.vtt" srclang="en" label="English">
<track kind="descriptions" src="descriptions.vtt" srclang="en" label="Descriptions" default>
</video>
<!-- descriptions.vtt -->
WEBVTT
00:00:00.000 --> 00:00:04.000
A woman in a blue suit stands at a whiteboard of accessibility diagrams.
00:00:08.000 --> 00:00:12.000
Close-up of her hands typing; the screen shows code with ARIA labels.A linked full text alternative (pass)
Alternatively, link a complete text document that covers both what is seen and what is heard — a valid way to meet 1.2.3 at Level A.
<!-- ✓ Full media alternative describing visuals + audio -->
<video controls width="600">
<source src="tutorial.mp4" type="video/mp4">
<track kind="captions" src="captions.vtt" srclang="en" label="English">
</video>
<a href="/tutorial-transcript">
Full text alternative: everything shown and said in this video
</a>Interactive demo
Play the mock video and toggle the audio description off to feel what a blind viewer loses. Then open the full text media alternative to see the other way of satisfying 1.2.3.
A video with audio description
Accessibility Training Video
A woman in a blue suit stands in front of a whiteboard covered with accessibility diagrams.
Press play and toggle the description off. With it off, a blind user gets only the dialogue — the actions, gestures, and on-screen code are lost. That gap is exactly what WCAG 1.2.3 asks you to close.
Common failures
- Publishing prerecorded video with meaningful visual content but neither an audio description nor a text alternative.
- Assuming captions are enough — captions convey the audio for deaf users but give blind users nothing about the visuals.
- Providing a 'transcript' that contains only the spoken dialogue and omits all the on-screen action and text.
- On-screen text, prices, results, or code shown visually but never spoken and never described.
- Relying on a description track the video player does not actually surface to users, with no fallback offered.
- Descriptions that talk over important dialogue or sound instead of sitting in the natural pauses.
- A media-alternative video used to justify skipping description, but never clearly labeled as an alternative to the text.
- Subjective or interpretive narration ('a beautiful, moving moment') instead of an objective account of what happens.
How to test for 1.2.3
- 1
Watch with the screen turned off
Listen to the video without looking. Note every moment where something important happens visually but is not conveyed by the soundtrack — an action, a change of scene, on-screen text. Each of those is content a blind user would miss unless it is described or provided in text.
- 2
Confirm one of the two mechanisms exists
Check that the video either offers an audio description (a selectable descriptions track or a described version) or links a full text media alternative. If neither is present and there is meaningful visual content, it fails.
- 3
Check the audio description covers the gaps
If a description track is provided, verify it actually describes the important visuals, sits in the natural pauses without covering key dialogue, and can be switched on. A track that exists but says too little still fails.
- 4
Check the text alternative is complete
If a media alternative is provided instead, read it on its own and confirm it conveys both the visual and the auditory content in order — not just a dialogue transcript. A reader should get the whole experience.
- 5
Apply the media-alternative-for-text exception carefully
If you are relying on the exception, confirm the video really does duplicate on-page text and is clearly labeled as an alternative to it. If the video adds anything the text does not cover, the exception does not apply.
Automated tools can flag a video that has no description track, but only a human can judge whether the visuals are actually covered. For a structured audit, work through the full WCAG 2.2 checklist.
Related Success Criteria
Provide alternatives for prerecorded audio-only and video-only content.
Captions are provided for all prerecorded audio content in synchronized media.
Captions are provided for all live audio content in synchronized media.
Audio description is provided for all prerecorded video content.
Sign language interpretation is provided for all prerecorded audio content.
Frequently asked questions
What is an audio description in WCAG 1.2.3?
An audio description is a separate narration track that describes the important visual information in a video — actions, characters, scene changes, on-screen text, and other things that carry meaning but are not spoken in the dialogue. The narration is inserted into the natural pauses between dialogue and sound effects so a person who cannot see the screen still follows what is happening. For prerecorded synchronized media (video with audio), 1.2.3 asks that this visual information be conveyed either through an audio description or through a full text media alternative. It is a Level A criterion under Guideline 1.2 Time-based Media.
When can I provide a full text media alternative instead of audio description?
1.2.3 gives you a choice: you can satisfy it with an audio description of the video, OR with a complete text alternative for the time-based media. A media alternative is a standalone document that describes everything a viewer would see and hear — all dialogue and narration plus all meaningful visual content, in the correct order. Providing this instead of an audio track is perfectly valid at Level A. Note, however, that Level AA's 1.2.5 Audio Description (Prerecorded) removes this option and requires an actual audio description, so if you are targeting AA the text-alternative route no longer satisfies you on its own.
What is the difference between 1.2.3 (Level A) and 1.2.5 (Level AA)?
Both are about audio description for prerecorded video, but they differ in strictness. 1.2.3 (Level A) lets you meet the requirement with either an audio description or a full text media alternative — you pick. 1.2.5 Audio Description (Prerecorded) (Level AA) is narrower: it requires an actual audio description track and does not accept a text-only alternative as a substitute. In practice, if you provide a proper audio description you satisfy both. If you only provide a text media alternative, you meet 1.2.3 but not 1.2.5.
What if there are no natural pauses in the dialogue for descriptions?
Standard audio description relies on the gaps between dialogue. When a video is so dense that there is no room to insert descriptions without talking over important audio, standard description cannot fit. The answer at Level A is to provide a full text media alternative instead, which is always allowed under 1.2.3. Separately, WCAG offers 1.2.7 Extended Audio Description (Prerecorded) (Level AAA), where the video is paused to make time for longer descriptions — but that is an AAA enhancement, not a requirement of 1.2.3.
What is the 'media alternative for text' exception?
1.2.3 does not apply when the media itself is an alternative to existing text and is clearly labeled as such. For example, if you have an article and you also publish a video that simply presents the same information for people who prefer to watch, that video is a media alternative for text. Because the equivalent information is already fully available in the text, you do not also need to audio-describe the video — provided it is clearly labeled as an alternative to that text.
Do audio descriptions need to cover every visual detail?
No. The goal is to convey the information that matters, not to narrate the screen exhaustively. Describe the visual content that is important for understanding — key actions, who is present, scene and setting changes, meaningful gestures and expressions, and any on-screen text or graphics that carry information. Skip decorative or redundant details, and never describe something the dialogue already makes clear. Descriptions should be objective and concise so they fit in the available pauses without competing with the original soundtrack.