Media Alternatives and Accessible Playback
Create captions, transcripts, audio descriptions, and controllable audio for prerecorded and live media under WCAG 2.2
Media accessibility depends on what the recording contains. WCAG 1.2.1–1.2.5 separates audio-only, video-only, prerecorded multimedia, live captions, and prerecorded audio description because each needs a different alternative. WCAG 1.4.2 separately requires a way to pause, stop, or independently control audio that starts automatically and continues for more than three seconds.
Choose the right alternative
- Prerecorded audio-only: provide a transcript containing the same information.
- Prerecorded video-only: provide either a text alternative or an audio track describing the visual information.
- Prerecorded synchronized media: provide captions and either audio description or, at Level A, a complete media alternative.
- Live synchronized media: provide live captions at Level AA.
- Autoplay audio: avoid it; when it lasts more than three seconds, expose an immediate pause, stop, or independent volume control.
Captions include dialogue and meaningful non-speech audio. A transcript is useful in addition to captions but does not replace required captions for synchronized media. Audio description describes meaningful visual information during available pauses; it is not the same as reading the transcript aloud.
Unlabelled Media vs. Accessible Playback Choices
View inaccessible code
<!-- A play button alone does not expose alternatives. -->
<video src="demonstration.mp4"></video>
<button>Play</button>Read transcript
The presenter opens the settings panel and selects Save.
View accessible code
<video controls preload="metadata" aria-describedby="media-summary">
<source src="demonstration.mp4" type="video/mp4" />
<track kind="captions" src="captions-en.vtt" srclang="en" label="English" default />
<track kind="descriptions" src="descriptions-en.vtt" srclang="en" label="English audio description" />
</video>
<p id="media-summary">A presenter opens Settings and selects Save.</p>
<details><summary>Read transcript</summary>…complete transcript…</details>Player and production checks
Verify keyboard operation, visible focus, control names and states, caption selection, caption accuracy and synchronization, transcript equivalence, audio-description coverage, and zoom/reflow. Human review is essential: automated tools cannot determine whether captions or descriptions convey the meaningful content.