Word to know
Alt text
A written description of an image, read aloud by screen readers.
Also called: image description, text for screen readers, what the picture shows, description for blind users
A sentence describing what a picture shows. People who cannot see the picture hear this instead, and it also appears if the image fails to load.
Using it in a prompt
Give every image alt text describing what it shows. Mark purely decorative images so screen readers skip them.
Left unasked, alt text comes back empty or as the file name, which is worse than nothing because it wastes the time of the person relying on it.
Describe what the image shows, not that it is an image. "Two people sharing a plate of pasta" beats "photo of food".