Audio and Video

Topic

Technique

WCAG AA Requirement

Prerecorded Audio-Only

Captions: Prerecorded video-only content MUST have synchronized captions.

Required WCAG 1.2.2

Transcript: All prerecorded audio MUST have a transcript of dialog, narration, and other meaningful sounds.

Required WCAG 1.2.1

Autoplay: A method MUST be provided to pause, stop, or hide any media content that begins playing automatically and which lasts 5 seconds or more.

Required WCAG 2.2.2

Audio Control: A mechanism MUST be provided to stop, pause, mute, or adjust volume for audio that automatically plays on a page for more than 3 seconds.

Required WCAG 1.4.2

Sign Language: Prerecorded audio-only content MAY include sign language interpretation.

best practice

Background Sounds: Background sounds in prerecorded audio-only content SHOULD be minimized (20dB lower than foreground sounds, except for occasional sounds of no more than 2 seconds) or eliminated during narration or dialog, or a method must be available to turn off background sounds.

best practice

Prerecorded Video-Only (and video-like animations)

Alternative Text: Prerecorded video-only MUST include a text description.

Required WCAG 1.2.1

Captions: Prerecorded video-only content MUST have synchronized captions.

Required WCAG 1.2.2

Audio Description: Prerecorded video-only content MUST include an audio description (narrated video description) of important visual content.

Required WCAG 1.2.5

Autoplay: A method MUST be provided to pause, stop, or hide any media content that begins playing automatically and which lasts 5 seconds or more.

Required WCAG 2.2.2

Flashing Content: A page MUST NOT contain content that flashes more than 3 times per second unless that flashing content is sufficiently small, the flashes are of low contrast, and do not violate general flash thresholds.

Required WCAG 2.3.1

Prerecorded Multimedia

Alternative Text: Prerecorded video-only MUST include a text description of important visual content that is not conveyed through the audio (this can be included in the transcript).

Required WCAG 1.2.1

Transcript: Prerecorded video-only MUST have a text transcript of dialog, narration, and other meaningful sounds.

Required WCAG 1.2.1

Captions: Prerecorded video-only content MUST have synchronized captions.

Required WCAG 1.2.2

Audio Description: Prerecorded video-only content MUST include an audio description (narrated video description) of important visual content.

Required WCAG 1.2.5

Autoplay: A method MUST be provided to pause, stop, or hide any media content that begins playing automatically and which lasts 5 seconds or more.

Required WCAG 2.2.2

Audio Control: A mechanism MUST be provided to stop, pause, mute, or adjust volume for audio that automatically plays on a page for more than 3 seconds.

Required WCAG 1.4.2

Flashing Content: A page MUST NOT contain content that flashes more than 3 times per second unless that flashing content is sufficiently small, the flashes are of low contrast, and do not violate general flash thresholds.

Required WCAG 2.3.1

Sign Language: Prerecorded video-only content MAY include sign language interpretation.

best practice

Background Sounds: Background sounds in prerecorded audio-only and prerecorded multimedia content SHOULD be minimized (20dB lower than foreground sounds, except for occasional sounds of no more than 2 seconds) or eliminated during narration or dialog, or a method must be available to turn off background sounds.

best practice

Live Audio-Only

Audio Control: A mechanism MUST be provided to stop, pause, mute, or adjust volume for audio that automatically plays on a page for more than 3 seconds.

Required WCAG 1.4.2

Autoplay: A method MUST be provided to pause, stop, or hide any media content that begins playing automatically and which lasts 5 seconds or more.

Required WCAG 2.2.2

Background Sounds: Background sounds in live audio-only content SHOULD be minimized (20dB lower than foreground sounds, except for occasional sounds of no more than 2 seconds) or eliminated during narration or dialog, or a method must be available to turn off background sounds.

best practice

Captions: Live audio-only content SHOULD have synchronized captions.

best practice

Live Video-Only

Captions: Live video-only content MUST have synchronized captions.

Required WCAG 1.2.4

Autoplay: A method MUST be provided to pause, stop, or hide any media content that begins playing automatically and which lasts 5 seconds or more.

Required WCAG 2.2.2

Flashing Content: Live video-only content MUST NOT contain content that flashes more than 3 times per second unless that flashing content is sufficiently small, the flashes are of low contrast, and do not violate general flash thresholds.

Required WCAG 2.3.1

Alternative Text: Live video-only MUST include a text description.

Required WCAG 1.2.1

Audio Description: Live video-only content SHOULD include an audio description (narrated video description) of important visual content.

best practice

Live Multimedia

Captions: Live multimedia content MUST have synchronized captions.

Required WCAG 1.2.4

Audio Control: A mechanism MUST be provided to stop, pause, mute, or adjust volume for audio that automatically plays on a page for more than 3 seconds.

Required WCAG 1.4.2

Autoplay: A method MUST be provided to pause, stop, or hide any media content that begins playing automatically and which lasts 5 seconds or more.

Required WCAG 2.2.2

Background Sounds: Background sounds in live multimedia content SHOULD be minimized (20dB lower than foreground sounds, except for occasional sounds of no more than 2 seconds) or eliminated during narration or dialog, or a method must be available to turn off background sounds.

best practice

Flashing Content: A page MUST NOT contain content that flashes more than 3 times per second unless that flashing content is sufficiently small, the flashes are of low contrast, and do not violate general flash thresholds.

Required WCAG 2.3.1

Audio Description: Live multimedia content SHOULD include an audio description (narrated video description) of important visual content.

best practice

Page Background Sounds

Audio Control: A mechanism MUST be provided to stop, pause, mute, or adjust volume for audio that automatically plays on a page for more than 3 seconds.

Required WCAG 1.4.2

Autoplay: A method MUST be provided to pause, stop, or hide any media content that begins playing automatically and which lasts 5 seconds or more.

Required WCAG 2.2.2

If Informative: If the background sounds contain informative content, all of the requirements for prerecorded audio-only content apply (see above).

depends

Page Background Video

Autoplay: A method MUST be provided to pause, stop, or hide any media content that begins playing automatically and which lasts 5 seconds or more.

Required WCAG 2.2.2

Flashing Content: A page MUST NOT contain content that flashes more than 3 times per second unless that flashing content is sufficiently small, the flashes are of low contrast, and do not violate general flash thresholds.

Required WCAG 2.3.1

See the requirements for color contrast (for text and UI elements overlayed on top of video).

Required WCAG 1.4.3

If Informative: If the background video contains informative content, all of the requirements for prerecorded video-only content apply (see above).

depends

Media Players

Media players themselves MUST be fully accessible (in particular to keyboard users and screen reader users). See the requirements for:

  • Media player keyboard accessibility

  • Media player screen reader accessibility

  • Captions, transcripts, audio descriptions within the media player

  • User customization options within the media player

  • See also the requirements for Forms, User Input, and Validation

  • See also the requirements for Custom Widgets (JavaScript)

Required Multiple

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