1.2.3 Audio Description or Media Alternative (Prerecorded)

Who it helps

Blind people and people with low vision miss actions, on-screen text and scene changes that the soundtrack doesn't mention. A text alternative also helps deafblind people, who can read it on a braille display.

How to meet it

• Watch the video with your eyes closed and note what you miss, such as on-screen text, demonstrations or who is speaking.
• If the soundtrack already conveys everything important, no extra description is needed.
• Otherwise, add audio description: narration in natural pauses that describes key visuals, offered as a separate version or audio track.
• Or provide a media alternative: a full transcript of the dialogue and sounds, plus descriptions of important visuals, in order.
• If you aim for level AA, plan for audio description, because 1.2.5 doesn't accept a text alternative alone.
• Know the exception: a video that is a clearly labeled alternative for text already on the page is exempt.

Examples

<h2>How to export a report</h2>
<video controls src="/video/export-report.mp4">
  <track kind="captions" src="/video/export-report.en.vtt"
         srclang="en" label="English">
</video>

<h2>How to export a report</h2>
<video controls src="/video/export-report.mp4">
  <track kind="captions" src="/video/export-report.en.vtt"
         srclang="en" label="English">
</video>
<p><a href="/export-report-transcript">Read the descriptive transcript</a>,
  including every step shown on screen.</p>

<h2>How to export a report</h2>
<video controls src="/video/export-report.mp4">
  <track kind="captions" src="/video/export-report.en.vtt"
         srclang="en" label="English">
</video>
<p><a href="/video/export-report-described.mp4">
  Watch with audio description</a></p>

Common mistakes

• Treating a captions file as the text alternative, even though captions cover sound, not visuals.
• Writing a transcript of the dialogue only, without describing what happens on screen.
• Showing important text, like a URL or a price, on screen without saying it aloud.
• Assuming a recorded talk needs no description while slides with key points go unread.

Related criteria

• 1.2.5 Audio Description (Prerecorded)
• 1.2.8 Media Alternative (Prerecorded)
• 1.2.2 Captions (Prerecorded)
• 1.2.7 Extended Audio Description (Prerecorded)

Official W3C explanation of 1.2.3