WCAG 1.2.8: Media Alternative (Prerecorded)
Captions serve people who cannot hear; audio description serves people who cannot see. For someone who is deafblind, neither works. This AAA criterion requires a full descriptive transcript — dialogue, sounds, and visual information in sequence — so the entire video can be read as text, including on a braille display.
The success criterion, in full
An alternative for time-based media is provided for all prerecorded synchronized media and for all prerecorded video-only media.
An “alternative for time-based media” is a WCAG-defined term: a document including correctly sequenced text descriptions of time-based visual and auditory information, which also provides a means of achieving the outcomes of any time-based interaction. Media that is a labelled alternative for text is exempt.
AAA context: completing Guideline 1.2
At Level A, 1.2.3 lets you provide either an audio description or a media alternative for prerecorded video. Level AA (1.2.5) makes audio description mandatory. 1.2.8 completes the picture at AAA by making the text alternative mandatory too — and by extending coverage to video-only media, such as silent screen recordings and animations.
The result at AAA is belt and braces: a Deaf user has captions and sign language (1.2.6), a blind user has audio description (1.2.5, 1.2.7), and a deafblind user — or anyone who simply prefers text — has the full descriptive transcript this criterion requires.
What the media alternative must contain
All dialogue, attributed
Every spoken word, with speaker names or roles, in the order it occurs — exactly what a caption file contains, but as flowing readable text.
Meaningful sounds
Non-speech audio that carries information: alarms, applause, a phone ringing, music that sets a scene. The same content captions convey in brackets.
Important visual information
Actions, scene changes, on-screen text, charts, facial expressions, and anything else a sighted viewer relies on — the content audio description conveys.
Correct sequence and interactions
Descriptions interleaved with dialogue in story order. If the media is interactive (for example, branching video), the transcript must provide a way to achieve the same outcomes.
✓ Passes
- A “Descriptive transcript” link under the video leading to structured HTML with scene descriptions and attributed dialogue.
- A silent product animation accompanied by a text walkthrough of everything it shows.
- A transcript on the same page, in a disclosure region directly below the player.
✗ Fails
- A dialogue-only transcript (a raw caption dump) with no description of the visuals.
- A summary — “this video demonstrates our dashboard” — instead of an equivalent account.
- A transcript that exists but is unlinked and unfindable from the video itself.
Markup patterns
1. Video with an adjacent descriptive transcript
Keep the transcript in the DOM near the player, behind a native disclosure so it does not overwhelm the page.
<figure>
<video controls src="/media/release-tour.mp4">
<track kind="captions" src="/media/release-tour.vtt"
srclang="en" label="English" default />
</video>
<figcaption>Product release tour, 4 min 20 s.</figcaption>
</figure>
<details>
<summary>Descriptive transcript</summary>
<section aria-label="Descriptive transcript of the release tour">
<h2>Descriptive transcript</h2>
<p><em>[The presenter stands beside a large dashboard screen
showing a line chart trending upward.]</em></p>
<p><strong>Maya (presenter):</strong> This quarter we shipped
three features our customers asked for most.</p>
<p><em>[She clicks “Reports”. A panel slides in
listing: Exports, Scheduling, Alerts.]</em></p>
<p><strong>Maya:</strong> Let’s start with exports…</p>
</section>
</details>2. Video-only media (silent demo) with a text walkthrough
1.2.8 explicitly covers video with no audio track at all. A numbered walkthrough of the on-screen actions is the natural alternative.
<video controls muted src="/media/setup-silent.mp4"
aria-describedby="setup-alt"></video>
<section id="setup-alt">
<h2>What the video shows</h2>
<ol>
<li>The user opens Settings and selects the API tab.</li>
<li>They select “New key”; a dialog shows the
generated key with a Copy button.</li>
<li>They paste the key into the CLI prompt; the terminal
prints “Authenticated”.</li>
</ol>
</section>3. Link to a transcript on its own page
<p class="media-alternatives">
<a href="/media/release-tour-transcript">
Read the descriptive transcript of this video
</a>
</p>How to test for 1.2.8
- 1
Inventory prerecorded video
List all prerecorded synchronized media and all prerecorded video-only media. Exclude only media that is itself a labelled alternative for text.
- 2
Locate the alternative from the media
Starting at each video, confirm you can reach the transcript in one obvious step — on the page, in a disclosure, or via a clearly named adjacent link.
- 3
Read the transcript without playing the video
The acid test: does the text alone give you the full story? Note any moment where you would need to watch or listen to understand — each one is a gap.
- 4
Compare against the video for completeness and order
Play the video alongside the transcript. Check that all dialogue, meaningful sounds, and essential visuals appear, correctly attributed and in the same sequence.
- 5
Check interaction outcomes and readability
If the media involves interaction, the alternative must offer a way to achieve the same outcomes. Confirm the transcript is real, structured text — readable by screen readers and braille displays, not an image or inaccessible PDF.
Common failures
- Publishing the caption file's text as the 'transcript' — dialogue only, with none of the visual information described.
- Summarizing instead of transcribing: a paragraph about the video is not an equivalent for the video.
- Omitting on-screen text, chart data, or demonstrated steps that a sighted viewer would rely on.
- Losing the sequence — grouping all description at the top and all dialogue below, so the story cannot be followed.
- Forgetting video-only media: silent screen recordings and animated walkthroughs need a media alternative too.
- Serving the transcript as a scanned or untagged PDF that a screen reader or braille display cannot read.
Frequently asked questions
What does WCAG 1.2.8 Media Alternative (Prerecorded) require?
It requires that an alternative for time-based media — a full descriptive text transcript — is provided for all prerecorded synchronized media (video with audio) and for all prerecorded video-only media. The transcript must tell the whole story: dialogue attributed to speakers, meaningful sounds, descriptions of important visual information, and the outcomes of any interactions, all in the correct sequence, so that reading it is a genuine equivalent to watching the video. It is a Level AAA criterion from WCAG 2.0, unchanged in 2.2.
How is a media alternative different from a normal transcript or captions?
Captions are timed text for the audio only, viewed alongside the video. A basic dialogue transcript covers only what was said. An 'alternative for time-based media' goes further: it interleaves the dialogue with descriptions of what happens visually — actions, scene changes, on-screen text, charts — in reading order, and describes the result of any user interaction the media involves. The W3C often calls this a descriptive transcript. Someone who cannot see or hear the video at all should lose nothing by reading it instead.
Who primarily benefits from 1.2.8?
People who are deafblind are the core audience: captions are invisible to them and audio description inaudible, so a text document readable by a refreshable braille display is the only way to access the content. The transcript also serves people with limited bandwidth or no media player, people who process text better than time-based media, and anyone who wants to search, skim, translate, or quote the content — plus it makes the material indexable by search engines.
How does 1.2.8 relate to 1.2.3 Audio Description or Media Alternative?
1.2.3 (Level A) gives a choice for prerecorded video with audio: provide either an audio description or a media alternative. At Level AA, 1.2.5 mandates the audio description branch. 1.2.8 (Level AAA) mandates the media-alternative branch as well — so at AAA, dense video content ends up with captions, audio description, and a full descriptive transcript. If you already wrote a media alternative to satisfy 1.2.3, the same document satisfies 1.2.8.
Does 1.2.8 apply to audio-only content like podcasts?
No. Prerecorded audio-only content is covered by 1.2.1 (Level A), which already requires a transcript-style alternative. 1.2.8 scopes to prerecorded synchronized media (video with an audio track) and prerecorded video-only media (video with no audio, such as a silent screen demo). As with all of Guideline 1.2, media that is itself a labelled alternative for text is exempt.
Where should the transcript live and how should it be linked?
Either on the same page as the media, immediately adjacent to it, or on a separate page linked directly from beside the player. The link or heading should name it clearly — for example 'Descriptive transcript' — and the transcript should be plain, structured HTML: headings for scenes, paragraphs for narration and description, and speaker names before dialogue. Avoid burying it inside a PDF or behind multiple navigation steps; discoverability is part of usability here.
Related Success Criteria
Provide alternatives for prerecorded audio-only and video-only content.
Captions are provided for all prerecorded audio content in synchronized media.
Audio description or full text alternative is provided for prerecorded video content.
Captions are provided for all live audio content in synchronized media.
Audio description is provided for all prerecorded video content.