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Level AAWCAG 2.0

1.2.4 Captions (Live)

Captions are provided for all live audio content in synchronized media.

Last reviewed: September 9, 2026

Understanding 1.2.4

This criterion extends captioning to real-time content such as webinars, livestreams, and live broadcasts, ensuring deaf and hard-of-hearing users can follow live events as they happen rather than only after the fact. Because the content isn't prerecorded, captions must be produced in real time, typically by a live captioner (CART) or a sufficiently accurate live speech-to-text service.

How to Meet It

Use a professional live captioning (CART) service or a real-time speech-to-text engine integrated with your streaming/conferencing platform (most enterprise webinar tools like Zoom, Teams, and YouTube Live support this). Assign a live captioner in advance for scheduled events, and instruct speakers to pause for questions and speak clearly to improve caption accuracy.

Frequently Asked Questions

Is automatic live speech-to-text (like Zoom's built-in captions) sufficient?

It can satisfy the letter of the criterion if enabled, but accuracy varies significantly with accents, audio quality, and multiple speakers. For high-stakes events, a human live captioner (CART) is strongly recommended.

Does a recorded replay of a live event need separate captions?

Yes. Once the live event becomes archived/on-demand content, it is now 'prerecorded' and falls under 1.2.2, so the live captions should be reviewed and corrected for the recorded version.

Related Success Criteria

1.2.1 Audio-only and Video-only (Prerecorded)1.2.2 Captions (Prerecorded)1.2.3 Audio Description or Media Alternative (Prerecorded)1.2.5 Audio Description (Prerecorded)

Quick Facts

Criterion1.2.4
LevelAA
IntroducedWCAG 2.0

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