Accessibility of video, animation and audio content

The accessibility of videos and audio embedded in content (Web page, Office document, etc.) goes through:

  • these videos, animations and audios themselves must be accessible;


  • the interface which allows the distribution of this content must be accessible.

Videos, audios, and animated components

For video or audio to be accessible, the following must be attached to the content:

  • A full transcription (sufficient for an audio file),
  • Subtitles,
  • Audio description, if necessary.

All other relevant criteria such as color contrasts must also be enforced.

Transcript #

Full transcription is the necessary and sufficient solution to make an audio file accessible.

The transcription must reproduce textually all important informations conveyed by the content, these can be:

  • the dialogues
  • messages displayed on the screen
  • any graphics and animations that bring information
  • the name and title of person
  • the name of things (buildings, products ...)
  • the place
  • what happens in the video
  • The settings of the video (quality, black and white ...)

It must be provided in text, HTML (to be preferred) or Word and must be immediately after the video.
The transcription can optionally be enhanced with images, if necessary.

Perimeter: all.

Captions #

Captions are a text version of the speech and sound on the video. They are displayed over the video. Captions should appear at the same time as the sound they are captioning and appear onscreen long enough to be read. Closed captions have to be preferred over open captions as they can be set on or off by the viewer while open captions are displayed to all viewers. They are mainly needed for users with hearing disabilities.

Perimeter: videos, animated components.

Audio descriptions #

Audio descriptions are separate audio tracks containing speech that describes the action, characters, and scenes of a video. It is played along with the video and it lets blind and vision-impaired users know what’s happening on the screen.
Audio description is not needed for talking heads only, or for text on slides as long as the slide text is included into what is said. Audio description might be needed for components like charts and diagrams.

Perimeter: videos, animated components.

Do not play contents automatically when the page loads #

This can be confusing for many users, and the sound can interfere with assistive technologies such as screen readers.
When reading content, check:

  • Let the user control the video, animation or audio (do not automatically start playback when the page loads),
  • For a video or animation, it must be free of any element that flashes more than three times per second.

Perimeter: all.

Choose an accessible media Player #

The video player used must allow:

  • Captions and audio description supported,
  • On/off command for captions, audio description and setup menu accessible to keyboard-only users (buttons and controls usable without a mouse and properly labeled),
  • To modify the display parameters of the subtitles (at least: the size of the text and the colors of the text / background).

Perimeter: all.

For more detailed information #