Image description

A detailed textual representation of an image's content, typically longer and more comprehensive than alt text. While alt text is a concise attribute embedded in HTML for screen readers, image descriptions may appear as visible captions, be provided via the longdesc attribute or aria-describedby, or be generated on demand by AI vision-to-language models. Image description guidelines (such as those from the DIAGRAM Center, W3C, and WebAIM) recommend including information about the image's subject, setting, actions, colours, text, and emotional tone, tailored to the context in which the image appears. Research has shown that blind and low-vision users' information needs vary significantly by image context — news, shopping, social media, and educational content each require different descriptive priorities.