Perceivable · Level AA · 1.2.4
Captions (Live)
Live audio-video content — a livestream, a webinar, a live-broadcast event — needs real-time captions too, not just prerecorded video. Same idea as 1.2.2, extended to content that's happening live.
- Deaf / hard of hearing
How to recognize it
Watch a livestream or live webinar and check whether captions are running alongside it: an event stream with speech and no live caption track shuts out anyone deaf or hard of hearing from the entire broadcast, in real time, with no way to catch up afterward unless a recording with captions gets posted separately later. This is distinct from 1.2.2 — a video that's already recorded and sitting on a page is a prerecorded-captions problem; a broadcast happening right now, with people watching it live, is this criterion.
How to fix it
Provide live captioning for the audio during the broadcast — either through a live human captioner/stenographer or a reliable real-time automatic captioning service integrated into the stream. If a recording of the event is posted afterward, make sure that recording gets proper reviewed captions too, since the live captions used during the broadcast are often rougher than what a recording deserves.
Example
Avoid
<!-- live webinar player embedded with audio, no caption option offered during the broadcast -->Prefer
<!-- live webinar player with a live caption track enabled, provided by a captioner or real-time captioning service -->