audio must have alternative

Definition audio elements must have caption or text transcription of the audio content.
  • Captions and text transcripts provide a means for people cannot hear the audio to understand the audio content.
  • Some types of learning disabilities affect speech perception, captions and text transcripts provide an alternative way to understand the audio content.
  • When the language of the audio is different than the native language of the listener, captions and text transcripts support the listner in understanding the audio content.
  • HTML4 Legacy Techniques (Required)
  • HTML5 and ARIA Techniques (Required)
WCAG 2.0 Success Criteria

1.2.1 Audio-only and Video-only (Prerecorded) (Level A, Primary Success Criterion)

Rule Category Audio/Video
Scope Element
Target Resources audio elements
  • audio
  • track
  • Use the track element to add captioning to the audio content.
  • Use WebVTT to encode the timed stamped captioning information for the audio content.
  • Use aria-describedby to reference a text transcript of the audio content.
Manual Checks
  • When captions are enabled on the media player, check to make sure the captions visible.
  • If there is a caption make sure the captions accurately represents the audio content.
  • If there is a text transcript make sure the transcript accurately represents the audio content.
Informational Links