Video content (like instructional videos, ads or interviews) must have audio description.
On this page:
This ensures that information communicated visually in the video is available to people who cannot see it.
1.2.3 Audio Description or Media Alternative (Prerecorded): An alternative for time-based media or audio description of the prerecorded video content is provided for synchronized media, except when the media is a media alternative for text and is clearly labeled as such. (Level A)
See the W3C’s detailed explanation of this guideline with techniques and examples.
Note: pre-recorded videos without sound are covered somewhere else in the W3C Web Content Accessibility Guidelines:
1.2.1 Audio-only and Video-only (Prerecorded): For prerecorded audio-only and prerecorded video-only media, the following are true, except when the audio or video is a media alternative for text and is clearly labeled as such: (Level A)
- Prerecorded Audio-only: An alternative for time-based media is provided that presents equivalent information for prerecorded audio-only content.
- Prerecorded Video-only: Either an alternative for time-based media or an audio track is provided that presents equivalent information for prerecorded video-only content.