How to make video and audio accessible
Audio description and descriptive transcripts for video
Audio description and descriptive transcripts describe important visual information in your video that isn't included in the main audio.
Audio description (AD) is additional audio commentary that explains what's happening in the video. It can include descriptions of body language, expressions and movements.
Descriptive transcripts are a text version of the speech, non-speech audio information and visual information that people need to understand the video.
They help people with visual impairments who cannot see or find it difficult to see the video.
When to use audio description
Pre-recorded videos with an audio track and visual information that is not included in the video audio must have an audio description. This can include visual information shown using:
- Graphs
- Text
- Demonstrations that show people how to do something
- Events and actions taking place
Pre-recorded videos with an audio track do not need an audio description if the visual content doesn't add information to the video. For example, decorative colours or patterns.
Pre-recorded videos that don't have an audio track (video-only) can either have an audio description or a descriptive transcript.
Live video streams also don't need an audio description.
How to add an audio description
There are three main ways. They are in order of difficulty.
Integrated audio description
The easiest way to make any visual information in your pre-recorded video accessible is to include it in the main video audio. Then you don't need to add an additional audio description.
To do this, make sure that when you're writing your video audio script, you include all the information you want the video to contain.
This Royal National Institute of Blind People (RNIB) video is an example of integrated audio description. The visual information in the video is included in the audio:
Add an additional audio file
If you have already created your video, you can add audio description as an additional audio file.
You should only do this if you can fit the audio description into gaps in the main audio. You can add the audio description to your video as part of the editing process.
Find out how to write and add audio description yourself on the W3C website.
This W3C video is an example of where audio description has been added as an additional audio file:
Create a new, alternative video
If you have already created your video and need to add audio description, you may not be able to fit audio description into gaps in your main audio.
If this is the case, you should create a second video that has integrated audio description.
Publishing multiple versions of your video
If you choose to add audio description by adding an additional audio file or creating a new, alternative video, you may wish to publish the original video as well as the version with audio description.
If you publish both, you must make both videos easy for people to find. You must also make it clear how they are different to help users pick the video to watch that best suits them.
For example, the RNIB include this information in the video name, and we have also included it in the following link text:
When to use a descriptive transcript
You must not provide a descriptive transcript instead of an audio description. But you can provide a descriptive transcript as well as an audio description, if you'd like to.
The only exception is pre-recorded videos that don't have an audio track (video-only) - you can choose to provide either an audio description or a descriptive transcript.
A descriptive transcript is text that includes:
- All informative audio, including speech and important sounds that help people understand the video. Essentially, all the text you should put in your video captions
- All important visual information that is not also in the audio
This means that descriptive transcripts benefit people who have a multi-sensory impairment, as well as people with a visual impairment.
You should make sure your transcript is a descriptive transcript, rather than a basic transcript. Basic transcripts are only a text version of the video audio, so they don't help people with visual impairments.
How to add a descriptive transcript
Find out how to create a transcript on the W3.org website.
Once you have created your descriptive transcript, you should make it easy for people to find. If you're embedding your video on a web page, we recommend publishing the descriptive transcript directly underneath the video. Or you can link to it instead.
For example, the video onW3C's Video Captions page has a link below it that takes users to the descriptive transcript.
You can also publish your descriptive transcript on YouTube. Find out how to format YouTube transcripts and upload them to videos on YouTube.