Goal
Provide complete audio descriptions even when natural pauses in video are too short.
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Level AAA
Success Criterion · WCAG 1.2.7
Extended Audio Description (Prerecorded)
Where pauses in foreground audio are insufficient to allow audio descriptions to convey the sense of the video, extended audio description is provided for all prerecorded video content in synchronized media.
Level AAAWCAG 2.0Perceivable1.2 · Time-based Media
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What to do
Pause the video to allow extended audio descriptions when regular pauses are insufficient.
Why it matters
Some videos have so much dialogue that there is no time for adequate audio descriptions without pausing the video.
Success criterion
What WCAG 1.2.7 requires
Summarized directly from the official Understanding document so teams can quote the requirement accurately.
Where pauses in foreground audio are insufficient to allow audio descriptions to convey the sense of the video, extended audio description is provided for all prerecorded video content in synchronized media.
Intent
Why WCAG created this requirement
- Extended audio description pauses the video to provide additional time for descriptions that cannot fit in natural gaps.
- This technique is necessary for content with continuous dialogue, rapid action, or complex visual information.
- The video freezes while the description is read, then resumes playback automatically.
- This goes beyond standard audio descriptions (1.2.5) which only use existing pauses in the audio.
Benefits
Who gains when you pass
- Blind users can access dialogue-heavy content that would otherwise be impossible to fully describe.
- Complex visual sequences (action scenes, detailed demonstrations) can be thoroughly explained.
- Users receive complete information about visual content rather than abbreviated descriptions squeezed into short pauses.
- Educational and training content with dense visual information becomes fully accessible.
- Fast-paced content (documentaries, action films, sports) can be made accessible without sacrificing description quality.
Why it matters
User impact when this criterion fails
Summaries drawn from the Understanding document help you socialize impact statements with product stakeholders.
Without extended audio descriptions, fast-paced or dialogue-heavy videos leave blind users with incomplete understanding of visual content.
Important visual details may be omitted when descriptions must fit into brief natural pauses.
Action sequences, complex demonstrations, and rapid scene changes become inaccessible.
Educational value is diminished when visual concepts cannot be fully explained.
Overview
When a video has continuous dialogue or sound with few natural pauses, standard audio descriptions cannot adequately convey all the visual information. Extended audio descriptions solve this by automatically pausing the video playback to allow the describer more time to explain what is happening visually. Once the description is complete, the video resumes. This Level AAA criterion ensures that even fast-paced or dialogue-heavy content can be made fully accessible to blind and low vision users.
- Extended descriptions are only needed when standard audio descriptions cannot convey sufficient information.
- The video must pause programmatically—users should not need to manually pause and play.
- The pause should occur at logical points, not mid-word or mid-action when possible.
- Video playback should resume automatically after the extended description finishes.
- This technique may alter the viewing experience but ensures complete accessibility.
Reference: All summaries and highlights originate from Understanding WCAG 1.2.7 and the W3C quick reference.
Fast facts
- Conformance level
- Level AAA
- WCAG version introduced
- WCAG 2.0
- Principle
- Perceivable
- Guideline
- 1.2 · Time-based Media
Examples
Make success tangible for teams
Share pass/fail snapshots to coach designers, engineers, QA, and content authors.
Fast-paced documentary
Pass
A nature documentary pauses during a rapid hunting sequence: "[Video pauses] The cheetah accelerates to full speed, closing the gap. The gazelle zigzags left, then right. Dust clouds rise as both animals reach the watering hole. [Video resumes]"
Fail
A nature documentary plays through the hunting sequence with only a brief "the cheetah chases the gazelle" squeezed into a 2-second pause.
Technical training
Pass
A software tutorial pauses to describe a complex interface: "[Pause] The dashboard shows five panels: top-left contains the project tree, top-right shows the code editor with syntax highlighting, bottom-left displays the console output... [Resume]"
Fail
A fast-paced tutorial only says "as you can see on screen" because there is no pause to describe the detailed interface.
Dialogue-heavy drama
Pass
During a scene with continuous dialogue, the video pauses between lines to describe: "[Pause] Sarah's expression shifts from confusion to realization. She glances at the photograph on the desk. [Resume]"
Fail
A dramatic scene has no description of character expressions or actions because characters speak continuously.
Sports highlight
Pass
A basketball highlight reel pauses between plays: "[Pause] Johnson receives the pass at the three-point line. He fakes left, drives right, spins past two defenders, and elevates for a reverse layup. [Resume]"
Fail
A sports highlight plays at normal speed with descriptions limited to "he scores" because action is continuous.
Evidence to keep
Document conformance decisions
Capture artifacts for VPATs, procurement reviews, and regression testing.
- Document which videos require extended descriptions vs. standard descriptions.
- Store extended description scripts with timestamp markers for pause points.
- Note the technical implementation used for video pausing (player, format, scripts).
- Track runtime differences between standard and extended description versions.
- Keep user feedback on extended description quality and timing.
- Document the criteria used to determine when extended descriptions are needed.
Official resources
Deep dives and supporting material
Keep these links handy when writing acceptance criteria or responding to audits.
Understanding 1.2.7
Official W3C interpretation, techniques, and intent for Extended Audio Description (Prerecorded).
Quick Reference 1.2.7
Filterable list of sufficient techniques and failures.
Technique G8
Providing a movie with extended audio descriptions.
Technique SM1
Adding extended audio description in SMIL 1.0.
Technique SM2
Adding extended audio description in SMIL 2.0.
DCMP Extended Description Guide
Described and Captioned Media Program guide on extended descriptions.
Implementation checklist
Capture progress and blockers
- Review videos to identify where natural pauses are insufficient for adequate description.
- Write extended description scripts that fully convey visual information for complex scenes.
- Implement technology that can pause video playback at designated points.
- Record extended audio descriptions with appropriate pacing.
- Synchronize pause points with the video timeline.
- Test that video pauses and resumes correctly at each extended description point.
- Provide a way for users to enable/disable extended audio descriptions.
- Consider offering both standard and extended description versions when appropriate.
Testing ideas
Prove conformance with evidence
- Identify videos with dialogue-heavy or fast-paced content where standard descriptions are insufficient.
- Verify extended audio description is available for these videos.
- Enable extended descriptions and play through the video.
- Confirm the video pauses at appropriate points for extended descriptions.
- Verify descriptions adequately convey the visual information.
- Check that video resumes automatically after each extended description.
- Test the toggle mechanism to enable/disable extended descriptions.
- Compare visual content against descriptions to ensure completeness.
Related success criteria
More from Time-based Media (1.2)
WCAG 1.2.1Audio-only and Video-only (Prerecorded)Level AWCAG 1.2.2Captions (Prerecorded)Level AWCAG 1.2.3Audio Description or Media Alternative (Prerecorded)Level AWCAG 1.2.4Captions (Live)Level AAWCAG 1.2.5Audio Description (Prerecorded)Level AAWCAG 1.2.6Sign Language (Prerecorded)Level AAAWCAG 1.2.8Media Alternative (Prerecorded)Level AAAWCAG 1.2.9Audio-only (Live)Level AAA