Section 1.2: Time-Based Media
This section of WCAG 2.1 outlines guidelines for making time-based media, including audio and video content, accessible to all users. These guidelines focus on providing alternatives, synchronization, and ensuring clarity for assistive tools.
1.2.1 Audio-only and Video-only (Prerecorded)
For audio-only content, provide a text transcript so that users who cannot hear can access the information. For video-only content, provide a text description or audio track describing the visuals.
- Example: A podcast episode should include a transcript with the entire conversation written out.
- Example: A silent instructional video on cooking should have an audio description of each step shown visually.
1.2.2 Captions (Prerecorded)
Ensure that all prerecorded videos with audio include synchronized captions to make the content accessible to users who are deaf or hard of hearing.
- Example: Below is a prerecorded video demonstrating captions: Video with Captions
1.2.3 Audio Description or Media Alternative (Prerecorded)
Provide an audio description or a text alternative for video content. This makes visual information accessible for users who are blind or visually impaired.
- Example: Below is a prerecorded video demonstrating Audio Description: Video with Audio Description
1.2.4 Captions (Live)
For live audio or video content, provide captions to make it accessible to users who are deaf or hard of hearing.
- Example: Live-streamed sports events should include real-time captions describing the commentary and game events.
1.2.5 Audio Description (Prerecorded)
For prerecorded video content, ensure that audio descriptions are included to describe key visual elements for blind or visually impaired users.
- Example: A movie should provide an audio description track that narrates visual scenes like "A character walks into a dimly lit room and picks up a mysterious object."
1.2.6 Sign Language (Prerecorded)
If sign language interpretation is necessary, include it as part of the video content or provide a separate video track.
- Example: An educational video about health could include a corner overlay with a sign language interpreter translating the dialogue.
1.2.7 Extended Audio Description (Prerecorded)
Extended audio descriptions may be necessary for videos with rapid visual changes, requiring pauses in the video to narrate all important information.
- Example: A fast-paced product demo video might include extended audio descriptions during pauses, explaining key transitions between scenes.
1.2.8 Media Alternative (Live)
For live audio-only or video-only content, provide a text alternative or other synchronized media alternatives to make the content accessible.
- Example: A live radio broadcast could provide a text feed summarizing the key points being discussed.