Principle 1 Perceivable · Guideline 1.2: Time-based Media
1.2.3 Audio Description or Media Alternative (Prerecorded)
What can only be seen must also be available in sound or text.
What this means in practice
At level A you may choose: audio description in the dialogue gaps, or a full text version of the video. Note that at level AA text alone is no longer enough – 1.2.5 requires the audio description.
Normative wording
The binding text lives at the W3C. What you read here is our own faithful rendering – not a quotation.