Captions (Live)
Live audio in synchronized media — webinars, live streams, virtual events — must carry real-time captions. Auto-captions can qualify if accuracy is high enough, but professional CART captioning is the safe bet.
What it asks
Any live broadcast that combines audio and video — a webinar, town hall, conference live stream, customer-support video call recorded for replay — must carry synchronized captions as it happens. The SC covers the live transmission, not the recording (a later recording falls under 1.2.2). Captions must capture speech and identify speakers in real time.
How to meet it
- Hire a professional CART (Communication Access Realtime Translation) captioner for high-stakes events — earnings calls, public-sector briefings, large keynotes.
- Enable Zoom / Teams / Webex live captions for internal webinars, and check the accuracy spot-test before going live.
- Display captions in a fixed location with good contrast (white text on black background is the long-standing standard).
- Identify speakers when the stream cuts between multiple presenters or includes audience Q&A.
- Provide a way for participants to enable captions themselves rather than requiring an admin to toggle them on.
- Test the caption latency before the event — anything over 3-4 seconds breaks the experience.
Common failures
- Live streams with no captions of any kind, especially company all-hands and product launches.
- Auto-captions running with a 90%+ error rate on industry jargon, then never reviewed.
- Captions only visible to the host on Zoom because “live transcription” was never turned on for attendees.
- Sign language interpreter present but no captions — sign isn’t a substitute, deaf users who don’t sign are excluded.
- Captions overlap with on-screen presenter video, lower-third graphics, or chat, becoming unreadable.
Why it matters
Live captioning is the most expensive part of meeting WCAG AA for media-heavy organizations, and the most-cited gap in remediation audits. Major platforms (Zoom, Teams, YouTube Live) now ship usable auto-captions for free — there is no longer a technical excuse, only a process one.