Understanding WCAG 2.0

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Captions (Live):
Understanding SC 1.2.3

1.2.3 Captions (Live): Captions are provided for live synchronized media. (Level AA)

Note: If synchronized media is completely computer generated, it is not live and is subject to the requirements for prerecorded synchronized media in WCAG 2.0.

Intent of this Success Criterion

The intent of this Success Criterion is to enable people who are deaf or hard of hearing to watch real-time presentations. Captions provide the part of the content available via the audio track. Captions not only include dialogue, but also identify who is speaking and notate sound effects and other significant audio.

Specific Benefits of Success Criterion 1.2.3:

  • People who are deaf or have a hearing loss can access the auditory information in the synchronized media content through captions.

Examples of Success Criterion 1.2.3

Related Resources

Resources are for information purposes only, no endorsement implied.

Techniques and Failures for Success Criterion 1.2.3 - Captions (Live)

Each numbered item in this section represents a technique or combination of techniques that the WCAG Working Group deems sufficient for meeting this Success Criterion. The techniques listed only satisfy the Success Criterion if all of the WCAG 2.0 conformance requirements have been met.

Sufficient Techniques

  1. G9: Creating captions for live synchronized media AND G93: Providing open (always visible) captions

  2. G9: Creating captions for live synchronized media AND G87: Providing closed captions using any readily available media format that has a video player that supports closed captioning

  3. G9: Creating captions for live synchronized media AND G87: Providing closed captions using one of the following techniques:

Note: Captions may be generated using real-time text translation service.

Additional Techniques (Advisory) for 1.2.3

Although not required for conformance, the following additional techniques should be considered in order to make content more accessible. Not all techniques can be used or would be effective in all situations.

(none currently documented)

Failures for SC 1.2.3

The following are common mistakes that are considered failures of Success Criterion 1.2.3 by the WCAG Working Group.

(No failures currently documented)

Key Terms


text presented and synchronized with synchronized media to provide not only the speech, but also non-speech information conveyed through sound, including meaningful sound effects and identification of speakers

Note 1: In some countries, the term "subtitle" is used to refer to dialogue only and "captions" is used as the term for dialogue plus sounds and speaker identification. In other countries, subtitle (or its translation) is used to refer to both.

Note 2: Audio descriptions can be, but do not need to be, captioned since they are descriptions of information that is already presented visually.

synchronized media

audio or video synchronized with another format for presenting information and/or with time-based interactive components