1.2.4 Captions (Live)

Who it helps

Deaf and hard-of-hearing people can take part in live events only if speech appears as text while it happens. Live captions also help people in noisy places and people listening in a second language.

How to meet it

• Book a human real-time captioner (CART) for important events; people handle names, jargon and crosstalk best.
• Use a streaming or meeting platform that delivers live captions to viewers, and turn them on for every session.
• Automatic live captions are often less accurate, so test them with your speakers and vocabulary before you rely on them.
• Send the captioner the agenda, speaker names and key terms ahead of time.
• Show captions in the player or in a panel right next to it, and tell attendees where to find them.
• After the event, add edited captions to the recording, which then falls under 1.2.2.

Examples

<h2>Live: Product launch keynote</h2>
<video controls src="https://stream.example.com/keynote/live.m3u8"></video>

<h2>Live: Product launch keynote</h2>
<video controls src="https://stream.example.com/keynote/live.m3u8"></video>
<iframe title="Live captions for the keynote"
        src="https://captions.example.com/events/keynote"
        width="640" height="160"></iframe>

Common mistakes

• Adding captions to the recording after the event but not during the live stream.
• Turning on automatic captions without checking how they handle names and technical terms.
• Captioning the main speaker but dropping audience questions and panel crosstalk.
• Putting captions in a separate window that viewers are never told about.

Related criteria

• 1.2.2 Captions (Prerecorded)
• 1.2.9 Audio-only (Live)

Official W3C explanation of 1.2.4