WCAG 1.2.8 — Media Alternative (Prerecorded)
For Level AAA, the video itself isn't enough — even with captions and description. A full text alternative covering the audio AND the visuals must exist, so deafblind users have a way in too.
What this requires
For prerecorded synchronised media at Level AAA, a media alternative for time-based media must be provided. This is a full text document that conveys all the information in the video — dialogue, on-screen text, visual actions, sounds, music cues — in a form readable by a deafblind user using a refreshable braille display. It's the most demanding of the media criteria because it can't lean on either the auditory or the visual channel.
How AI coding tools fail this
AI tools generally don't produce these documents; the failure is in how they're surfaced. When a media alternative exists, code-generation tools often bury it as a footer link or omit it from the player UI entirely. The user who needs it most can't find it.
The second pattern: presenting an editorial recap or a marketing summary as if it were a media alternative. A "what we covered" blog post is not equivalent content. The media alternative has to reproduce the information, not interpret it.
Edge cases
- Captions + audio description ≠ media alternative. A deafblind user can't perceive either. The text document is the only path.
- The link must be discoverable to a screen-reader user before
they hit play. Putting it inside
<figcaption>adjacent to the video is reliable; a deep-buried "Resources" page is not. - Auto-generated transcripts are not adequate by themselves — they miss the visual track entirely.
- Pages of long-form video (lecture series, conference archives) often satisfy this via shared transcript pages, which is fine as long as the link is right next to each video.
How Jeikin handles this
This is a manual review item. The scanner records each <video> and
asks the reviewer whether a media alternative exists and is linked
adjacent to the video. The dashboard tracks the answer per video, with
a reminder for projects targeting AAA that a captions-only setup is
not enough.