Audio/Video Media Has Transcripts or Descriptions
What this criterion checks
This criterion maps to 1.2.1 Audio-only and Video-only (Prerecorded). A detailed plain-language description is maintained in the WebLens criteria catalogue; the WCAG sub-test breakdown below describes exactly what the agent checks and what it does not.
How it's assessed
WebLens walks each user journey, captures a screenshot at every step, and an agent reasons over that evidence. See the how WebLens works for the full pipeline and the deterministic checks layered in for accessibility.
Sub-test coverage
1.2.1 Audio-only and Video-only (Prerecorded) is broken into 3 sub-tests. Coverage is honest about where the agent is reliable, where it only partially checks the requirement, and where a human reviewer is still needed.
1 partial2 not covered
- Prerecorded audio-only has a text alternativePartial
Our tool checks that HTML5 audio elements include a track element with kind="captions". However, it cannot verify the quality or completeness of the transcript content, and only detects HTML5 audio elements — not audio embedded via third-party players or JavaScript-based audio.
- Media alternative exception checkNot covered
Determining whether media is a clearly labeled alternative for existing text content (and therefore exempt) requires human judgment. Not automatable.
- Prerecorded video-only has a text alternative or audio trackNot covered
Our Axe check (audio-caption) targets HTML5 audio elements only. Video-only content requiring text alternatives or audio tracks under 1.2.1 is not checked by this test. Video-specific caption checks are under our 1.2.2 test (accs-mdia-media_captions).
How reliable it is
This criterion is still building up testing data, so confirm its findings as you review. See Accuracy & confidence for how the confidence tags are set.