Perceivable · Level AA · Introduced in WCAG 2.0
WCAG 1.2.4: Captions (Live)
Published by whatisADA / Grow Wild Agency · Updated
What this criterion means
Live synchronized media needs captions for the live audio. Plan caption production and delivery as part of the event workflow rather than treating a later transcript as equivalent access.
A practical example
A live town-hall stream includes audience questions from microphones in the room. The caption feed must include those questions and identify changes of speaker, not only the prepared presentation.
How to check it
- Before the event, verify that the intended player exposes and displays the live caption feed.
- During a rehearsal, compare speech, speaker changes and meaningful sounds against the captions.
- Test the participant view on the devices used by the audience and check that captions do not cover essential content.
What can be missed
A recording captioned after the event does not supply live access. Accuracy and delay need operational monitoring; the presence of an automated caption service is only the start of that check.
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These are your observations, not automated results or a conformance certificate. A complete evaluation needs appropriate scope, supported technologies, all applicable criteria and relevant page states.
Primary sources and scope
This is independent implementation guidance with original examples. The linked standard contains the full definitions, exceptions and conformance requirements. A criterion or checklist alone does not establish legal applicability or whole-site conformance.