Sometimes an image is not sufficient to communicate information to a user. This could be for one of many reasons including:
- the user is vision-impaired
- the image is not localized
- the image failed to load
For this reason it is necessary to provide a text description of the image. A text description can:
- be read by a screen reader
- be localized to the user
- be used in place of an image if the image failed to load.
This same problem appears in many contexts and therefore the same solution of alt text appears in many contexts: alt text, alternative text.
Guides
- Authoring Meaningful Alternative Text | Section508.gov
- Alt text - Why It’s Important - Debbie Ridpath Ohi