WCAG 1.2.5 Audio Description: How to Add Described Video

Last updated: 2026-03-22

Level AA Perceivable WCAG 1.2.5

What This Criterion Requires

WCAG 1.2.5 requires that audio description is provided for all prerecorded video content in synchronized media. Audio description is a narration track that describes important visual information that is not conveyed through the existing audio track alone. This includes actions, scene changes, on-screen text, facial expressions, and other visual details that are essential to understanding the content. Unlike criterion 1.2.3 (Level A), which allows a text alternative as a substitute, 1.2.5 at Level AA specifically requires an audio description track. The description is typically inserted during natural pauses in the dialogue or narration. When natural pauses are insufficient, extended audio description (covered by 1.2.7 at Level AAA) may pause the video to allow the description to complete. Audio descriptions can be provided as a secondary audio track, a separate version of the video, or through a media player that supports audio description toggling.

Why It Matters

Audio descriptions are critical for users who are blind or have low vision, enabling them to understand visual content that is otherwise inaccessible. Without audio descriptions, a video tutorial showing how to use software, a product demonstration, or an educational lecture with visual slides would leave out essential information for these users. The visual components of video often carry meaning that is never spoken aloud, such as text on slides, gestures, physical demonstrations, or changes in scenery. People with cognitive disabilities may also benefit from the additional narration that reinforces and clarifies visual information. As video content becomes an increasingly dominant form of communication on the web, providing audio descriptions ensures that the full meaning of multimedia content reaches all users regardless of their ability to perceive the visual track.

Common Failures and How to Fix Them

Video player with no audio description track option

A prerecorded video contains important visual-only information such as on-screen demonstrations and text overlays, but no audio description track is available and the player offers no way to enable one.

Inaccessible 
<video controls>
  <source src="product-demo.mp4" type="video/mp4">
  <track kind="captions" src="captions-en.vtt" srclang="en" label="English">
</video>
Accessible 
<video controls>
  <source src="product-demo.mp4" type="video/mp4">
  <track kind="captions" src="captions-en.vtt" srclang="en" label="English">
  <track kind="descriptions" src="descriptions-en.vtt" srclang="en" label="Audio Description">
</video>
<button onclick="toggleAudioDescription()">Toggle Audio Description</button>

Audio description omits critical visual information

An audio description track exists but fails to describe key visual elements such as on-screen text, charts, or physical actions that are not communicated through the primary audio track.

Inaccessible 
WEBVTT - Audio Description

00:00:05.000 --> 00:00:08.000
A person is shown on screen.

00:00:15.000 --> 00:00:18.000
A chart appears.
Accessible 
WEBVTT - Audio Description

00:00:05.000 --> 00:00:08.000
Sarah, the presenter, stands at a podium
in front of a large projection screen.

00:00:15.000 --> 00:00:22.000
A bar chart displays quarterly revenue:
Q1 at 1.2 million, Q2 at 1.8 million,
Q3 at 2.1 million, and Q4 at 2.9 million dollars.

How to Test

  1. Play the video and identify all visual information that is not communicated through the existing audio or dialogue.
  2. Enable the audio description track (if available) and verify that all essential visual content is narrated during the descriptions.
  3. Check that the audio description does not overlap with important dialogue or narration in the primary audio track.
  4. Verify that the media player provides a visible, accessible control to toggle audio descriptions on and off.

CMS-Specific Guidance

This criterion commonly causes issues on these platforms:

Further Reading

Related WCAG Criteria