Audio and Video


  • You should provide a text equivalent of any audio content.


  • Text representation of the spoken word or any kind of sound
  • Captions make audio and video in the website accessible to those who do not have access to audio.

Who Benefits from Captioning and Transcripts?

  • Primarily for an audience who cannot hear the audio
  • Those with language barrier/second language
  • In noisy environments – gym, bar, airport, etc.
  • In quiet library settings where sound should be muted

There are two types of captions: Open and Closed.

Open Captions

  • Open captions cannot be turned off – they are always visible within the video.
  • Open captions are seen in some foreign films – Subtitle

Example: Captionlink Example

Closed Captions

  • Closed captions can be turned on and off by the viewer.
  • Closed captions are typically available on most television shows and commercials.
  • All television sets larger than 13″ produced after 1995 have to have built-in caption decoders.

Example: Magic Camp’s Fundraising at One World Theater

Audio Descriptions

  • Description of the visual content
  • Audio descriptions provide a description of the critical visual information being displayed that is not available otherwise — Comments like “John enters the room with a fearful look on his face.”
  • Providing Audio descriptions allows video content to be accessible to those with vision impairments.

Examples: Accessible Hamlet and Google Self-Driving Car Test

WCAG 2.0 Guidelines

1.1 Text Alternatives: Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language.

Where can I get more information?