Perceivable Guideline 1.2 Time-based Media

1.2.3 Audio Description or Media Alternative (Prerecorded)

Recorded video needs audio description or a full text alternative

Level A Needs a person to check

What it asks for, in plain English

When a recorded video shows things that matter but are not spoken aloud, for example a chart on screen, a step performed silently, or text shown in a caption card, that information has to reach people who cannot see it.

At Level A you have a choice: add audio description (a narrator describing the visuals in the gaps between speech) or provide a full text alternative, which is a transcript that includes the dialogue and describes what happens on screen in order.

A talking-head video where everything is said aloud already meets this; there is nothing visual to describe. At Level AA (1.2.5) the transcript option goes away and audio description is required.

This is an independent explanation. The binding wording is the W3C Recommendation, and the W3C's own Understanding 1.2.3 page has the full intent, techniques and definitions.

Who it affects

Someone who is blind hears 'as you can see here, the figures dropped sharply' and nothing else, because the figures were only on screen.

A person with low vision watching on a phone cannot make out the small on-screen text that names each step of the tutorial.

A colleague skimming for one fact searches the transcript and finds it in seconds instead of scrubbing through ten minutes of video.

How to check it

  1. Watch each video with your eyes shut, or with the screen off, and note every moment where you lose information.
  2. If there is an audio described version, play it and check those moments are now narrated.
  3. If there is a transcript instead, check it describes those moments in text, in the right place, rather than giving dialogue only.
  4. Confirm the described version or transcript is linked next to the video, not buried on another page.

What Websight checks for 1.2.3

Websight has no automated check for this criterion. It lists it in the manual checklist that comes with every report, so it is not forgotten.

Only a person can check this. A scanner cannot watch a video and decide whether what it shows is also spoken or written down.

Practical tips

  • Cheapest fix for new videos: have the presenter say what is on screen ('the June figure is 40 thousand, down from 65'). Then no separate description is needed.
  • If you already produce captions, extend the same file into a transcript with scene descriptions in brackets.
  • Describe what matters for the point of the video, not every visual detail.

Scan your page and see where 1.2.3 stands

Websight gives a score out of 100, explains each automated finding in plain English, and lists the checks a person still needs to do.

Add Websight to Chrome

Free scans, no account, nothing leaves your computer. Automated tools find only part of the problems; the extension says so on every report.