Level AAA

AAA-level: a full text alternative is required in addition to captions and audio description

1.2.8 Media Alternative (Prerecorded)

In Plain Language

[1.2.8 Media Alternative (Prerecorded)](https://www.w3.org/WAI/WCAG22/Understanding/media-alternative-prerecorded.html) is a Level AAA criterion that applies to any prerecorded synchronised media (video with an audio track). It requires a complete text alternative to the media -- a standalone document that conveys every piece of information a sighted, hearing viewer would receive: all dialogue, all non-speech audio, and all visual content including actions, scene changes, on-screen text, and interactive affordances[1].

The mechanism is distinct from the earlier video criteria. [1.2.3 Audio Description or Media Alternative](https://www.w3.org/WAI/WCAG22/Understanding/audio-description-or-media-alternative-prerecorded.html) at Level A lets an author pick one of two paths -- audio description *or* a text alternative[2]. [1.2.5 Audio Description](https://www.w3.org/WAI/WCAG22/Understanding/audio-description-prerecorded.html) at Level AA removes that choice and mandates audio description. At AAA, 1.2.8 layers on top: when 1.2.3 and 1.2.5 have been satisfied with audio description, a full text alternative is still required in addition[1]. It is not a substitute for captions or audio description -- it sits alongside them.

"Complete text alternative" is a specific structural claim, not a rebranded transcript. A dialogue-only transcript fails 1.2.8 because it drops the visual channel. The document has to read like a screenplay or scene-by-scene narration: time-stamped or scene-segmented headings, explicit speaker labels, bracketed descriptions of visual content (actions, settings, charts, on-screen text), bracketed non-speech audio cues (phone ringing, laughter, music stings), and embedded screenshots with descriptive `alt` text only where a visual cannot be conveyed in words alone.

Why It Matters

  • Deaf-blind users and users with severe combined vision and hearing loss cannot consume captions (visual) or audio description (auditory). A text alternative rendered through a refreshable braille display is the only channel that delivers both the dialogue and the visual information of a video to these users[1].
  • Readers who process written prose more reliably than synchronised audio-video -- including many users with cognitive and learning disabilities -- can pace, re-read, and search a text document in ways a timeline-based player does not allow.
  • A structured text alternative is the only artefact in the media bundle that is indexable by search engines, translatable by machine translation, and citable by line. Captions in WebVTT[3] are time-coded fragments, not a readable document; audio description is an audio track.
  • Procurement contexts that require a records-management copy of every published video (archival retention, FOIA response, regulated-industry review) are satisfied by the same document that satisfies 1.2.8, because a full media alternative is by construction a complete textual record of the media.

Examples

Do: Provide a full text alternative document linked from the video

<video controls>

  <source src='training.mp4'

    type='video/mp4'>

</video>

<a href='training-full-text.html'>

  Full text alternative

</a>

✔ A complete text document covers all dialogue, sounds, and visual information

<video controls>
  <source src="training.mp4"
          type="video/mp4">
  <track kind="captions" src="captions.vtt"
         srclang="en" label="English" default>
</video>

<!-- Full text alternative linked directly
     below the video player -->
<a href="training-full-text.html">
  Full text alternative for training video
</a>

<!-- The text alternative document includes:
     - All spoken dialogue with speaker IDs
     - Description of all visual content
     - Sound effects and music cues
     - On-screen text and graphics
     - Scene and setting descriptions -->
Don't: Provide only a dialogue transcript

<video controls>...</video>

<a href='transcript.txt'>Transcript</a>

✘ A dialogue-only transcript omits visual information -- the text alternative must describe everything a viewer would see and hear

<!-- FAILS 1.2.8: transcript only includes
     spoken dialogue, missing all visual
     information -->
<video controls>
  <source src="demo.mp4" type="video/mp4">
</video>
<a href="transcript.txt">Read transcript</a>

<!-- This transcript only contains:
     "Welcome to the demo. Click the blue
      button to continue."
     It omits: the instructor pointing to a
     screen, the diagram shown at 0:45, and
     the on-screen text that appears at 1:12.
     A full text alternative must describe
     ALL visual and auditory content. -->
Do: Include visual descriptions, sound cues, and speaker identification

Full text alternative excerpt:

[Scene: office setting, morning]
[Sound: phone ringing]
Narrator: "Every day, our support team..."
[On-screen text: 94% satisfaction rate]
[Visual: bar chart comparing 2024-2025 scores]

✔ All visual and auditory information is captured in the text document

<!-- Structure of a complete text alternative -->
<article class="media-alternative">
  <h1>Full Text Alternative: Customer Support
      Training Video</h1>

  <section>
    <h2>Scene 1: Introduction (0:00 - 0:45)</h2>
    <p><strong>[Scene: A bright office with rows of
    desks. Morning light through windows.]</strong></p>
    <p><strong>[Sound: Phone ringing, keyboard
    typing]</strong></p>
    <p><strong>Narrator:</strong> "Every day, our
    customer support team handles thousands of
    calls."</p>
    <p><strong>[On-screen text: 94% customer
    satisfaction rate]</strong></p>
    <p><strong>[Visual: Animated bar chart comparing
    2024 and 2025 satisfaction scores, showing an
    increase from 89% to 94%]</strong></p>
  </section>
</article>
Don't: Rely on captions alone as a text alternative

<video controls>

  <track kind='captions' ...>

</video>

✘ Captions cover only the audio track -- they do not describe visual-only content like charts, actions, or scene details that a full text alternative must include

<!-- FAILS 1.2.8: captions only convey the
     audio track, not visual information -->
<video controls>
  <source src="overview.mp4" type="video/mp4">
  <track kind="captions" src="captions.vtt"
         srclang="en" label="English" default>
</video>

<!-- Captions transcribe dialogue and sound
     effects but do not describe:
     - Visual demonstrations and actions
     - Charts, graphs, and diagrams
     - On-screen text and labels
     - Scene changes and settings
     A separate full text alternative document
     is required to meet 1.2.8. -->

How to Fix It

  1. Inventory every prerecorded synchronised media asset. Enumerate each `<video>` or embedded player whose source contains both an audio and a visual track. Audio-only and video-only assets fall under [1.2.1](https://www.w3.org/WAI/WCAG22/Understanding/audio-only-and-video-only-prerecorded.html)[4] and are out of scope for 1.2.8.
  2. Author a full text alternative document, not a transcript. The document must contain, in reading order: speaker-labelled dialogue, bracketed visual descriptions (setting, action, on-screen text, charts, diagrams), bracketed non-speech audio cues, and a representation of any interactive affordance the video shows (buttons, hyperlinks). A dialogue-only transcript fails because it drops the visual channel; [1.2.2 Captions](https://www.w3.org/WAI/WCAG22/Understanding/captions-prerecorded.html)[5] cover the audio track but do not substitute for the visual content 1.2.8 requires.
  3. Structure the document by scene or timestamp. Use `<h2>` per scene with an explicit time range ("Scene 1: Introduction (0:00 - 0:45)"). Scene segmentation gives screen-reader users a navigable landmark structure and lets a reader cross-reference back to the video timeline.
  4. Anchor the link directly to the player. Place an `<a>` with text like "Full text alternative for this video" immediately adjacent to the `<video>` element so the relationship is obvious in both the visual layout and the DOM reading order. A link buried in a separate "Resources" block fails discoverability.
  5. Bind the text alternative to the video's version. When the source video is re-cut, the text alternative is re-authored in the same change. A stale alternative is worse than none because it misrepresents the current media. Treat the text file as a build artefact of the video, not a separate document.
  6. Validate by reading the document without the video. The acceptance test is whether a reader who has never seen the video can reconstruct the full experience -- dialogue, who is speaking, what is happening on screen, what data is shown -- from the text alone. If they cannot, the alternative is incomplete regardless of word count.
  7. Remember 1.2.8 is additive, not alternative. At AAA, the text alternative is required in addition to the AA-level captions ([1.2.2](https://www.w3.org/WAI/WCAG22/Understanding/captions-prerecorded.html))[5] and audio description ([1.2.5](https://www.w3.org/WAI/WCAG22/Understanding/audio-description-prerecorded.html)) when the AA path chose audio description to satisfy [1.2.3](https://www.w3.org/WAI/WCAG22/Understanding/audio-description-or-media-alternative-prerecorded.html)[2][1]. Shipping the text alternative does not let you delete the caption track.

References

  1. [1] W3C (2023). Understanding Success Criterion 1.2.8: Media Alternative (Prerecorded). W3C, Accessed 2026-04-07. https://www.w3.org/WAI/WCAG22/Understanding/media-alternative-prerecorded.html ↩ ↩ ↩ ↩
  2. [2] W3C (2023). Understanding Success Criterion 1.2.3: Audio Description or Media Alternative (Prerecorded). W3C, Accessed 2026-04-07. https://www.w3.org/WAI/WCAG22/Understanding/audio-description-or-media-alternative-prerecorded.html ↩ ↩
  3. [3] W3C (2019). WebVTT: The Web Video Text Tracks Format. W3C, Accessed 2026-04-07. https://www.w3.org/TR/webvtt1/ ↩
  4. [4] W3C (2023). Understanding Success Criterion 1.2.1: Audio-only and Video-only (Prerecorded). W3C, Accessed 2026-04-07. https://www.w3.org/WAI/WCAG22/Understanding/audio-only-and-video-only-prerecorded.html ↩
  5. [5] W3C (2023). Understanding Success Criterion 1.2.2: Captions (Prerecorded). W3C, Accessed 2026-04-07. https://www.w3.org/WAI/WCAG22/Understanding/captions-prerecorded.html ↩ ↩