What is it?
Alternative text, or alt text, is a brief written description that communicates the purpose or essential information of an image to someone who cannot access it visually. Screen readers can announce alt text for photographs, illustrations, icons, diagrams, and other digital images. Making images accessible may also involve captions, nearby descriptions, tactile representations, or more detailed explanations when a short description cannot communicate the necessary information.
How to use it?
Consider why the image is included and describe the information a learner needs from it rather than listing every visible detail. Keep alt text concise for straightforward images and provide a longer description when a complex diagram, graph, or illustration requires more explanation. Mark purely decorative images as decorative so screen readers can skip them. When an image contains important text, provide that information as accessible text rather than relying on the image alone.
Why use it?
Images often carry information that is not repeated elsewhere in classroom materials. Without an accessible alternative, learners who are blind, have low vision, or access content nonvisually may miss important context or instructional content. Thoughtful image descriptions provide more equitable access while encouraging educators to identify what information a visual is actually intended to communicate.
