Understanding WCAG 2.0

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Audio-only and Video-only (Prerecorded):
Understanding SC 1.2.1


  • Prerecorded Audio-only: A text alternative is provided that presents equivalent information for prerecorded audio-only content.

  • Prerecorded Video-only: Either a text alternative or an audio track is provided that presents equivalent information for prerecorded video-only content.

Intent of this Success Criterion

The intent of this Success Criterion is to make information conveyed by prerecorded audio-only and prerecorded video-only content available to all users. Text alternatives used to make information accessible because they can be rendered through any sensory modality (for example, visual, auditory or tactile) to match the needs of the user.

For prerecorded video content, authors have the option to provide an audio track. This makes it possible for users with and without vision impairment to review content simultaneously. The approach can also make it easier for those with cognitive, language and learning disabilities to understand the content because it would provide parallel presentation.

See also Understanding Success Criterion 1.2.9 Live Audio-only

Specific Benefits of Success Criterion 1.2.1:

  • This Success Criterion helps people who have difficulty perceiving visual content. Assistive technology can read text alternatives aloud, present them visually, or convert them to braille.

  • Text alternatives may help some people who have difficulty understanding the meaning of prerecorded video content.

  • People who are deaf, are hard of hearing, or who are having trouble understanding audio information for any reason can read the text presentation. Research is ongoing regarding automatic translation of text into sign language.


  • Additionally, text alternatives support the ability to search for non-text content and to repurpose content in a variety of ways.

Examples of Success Criterion 1.2.1

Related Resources

Resources are for information purposes only, no endorsement implied.

(none currently documented)

Techniques and Failures for Success Criterion 1.2.1 - Audio-only and Video-only (Prerecorded)


Sufficient Techniques


Situation A: If the content is prerecorded audio-only:

  1. G158: Providing a full text transcript for the audio

Situation B: If the content is prerecorded video-only:

  1. G159: Providing a full text transcript of the video content

  2. Adding an audio track that describes the important video content and describing it as such (future link)

Additional Techniques (Advisory) for 1.2.1


  • Providing a transcript of a live audio only presentation after the fact (future link)

  • Linking to textual information that provides comparable information (e.g. for a traffic Webcam, a municipality could provide a link to the text traffic report.) (future link)

Key Terms



media alternative for text




information that is not live

text alternative



