Text-based alternatives to visual media
When using non-text content in your web pages – for example, images, video, audio or PowerPoint slides – you must provide a text-based alternative.
“Text alternatives are a primary way for making information accessible because they can be rendered through any sensory modality (for example, visual, auditory or tactile) to match the needs of the user. Providing text alternatives allows the information to be rendered in a variety of ways by a variety of user agents. For example, a person who cannot see a picture can have the text alternative read aloud using synthesized speech. A person who cannot hear an audio file can have the text alternative displayed so that he or she can read it. In the future, text alternatives will also allow information to be more easily translated into sign language or into a simpler form of the same language.”
In this article:
Add an image description (alt text)
- Go to the page where you want to insert an image.
- Add an image to the page.
In the Image window, enter a description of the image in the Description box:
alt(alternative) text, which is important for accessibility. For example, the
alttext Athena SWAN bronze award is better than asba-logo1.png or orange and blue logo.
If the image you are uploading is fully described in the text or is just for decoration, you can instead tick the checkbox This image is for decorative purposes only.
- is read aloud by assistive technology (for example, the JAWS screen reader) to make images' content and function accessible
- appears in place of the image if the image file does not load or the user has turned off images in their browser
- enables search engines to understand what information is in the image
Edit an image description
- Go to the page containing the image you want to edit.
- Go to Edit > Edit centre content or Edit right content.
- Right-click the image in the visual editor and select Image.
- In the Image window, change the
alttext in the Description box.
- Select the Insert button.
- When you have finished editing, select Publish.
Text-based alternatives for other visual media
When you add other visual media your pages – for example, video or audio – include audio-described captions and a transcript of your media. For example:
- captions (subtitles) in your video, with audio-description, that's a description of any sound within the video, as well as any spoken dialog
- video transcriptions in a text file – see Google's advice on how to make transcripts for YouTube or the text of a PowerPoint presentation in a separate text or PDF file
Email webteam at warwick dot ac dot uk
How to report a problem
Why are good image descriptions necessary?
Not all users can see images. Disabled visitors to your site may be using assistive technology which reads the page out loud, and this software will read the
alt text to find out what that image represented.
A good description covers the information the picture intends to convey rather than what the picture looks like. For example if your site included the twitter icon, the
alt text for this image could be
alt="Twitter"<span "> but it should not be "blue bird".
To save the software reading out unnecessary information, use the checkbox for purely decorative images.