Provide meaningful alt text for images

Approximately 2.2 billion people worldwide have vision impairment. Screen readers read the alt attribute aloud—without meaningful alt text, users who are blind receive no information about image content. Missing alt text also fails WCAG 2.1 Success Criterion 1.1.1, which is a Level A (minimum) requirement. Search engines also rely on alt text to index image content.

Quick Reference

• Every <img> must have an alt attribute—omitting it entirely violates WCAG 2.1 SC 1.1.1
• Decorative images use alt="" so screen readers ignore them
• Alt text should describe the image's purpose, not just its appearance
• Linked images: alt describes the link destination, not the visual

Check

Scan all elements in the codebase. Verify: 1) Every has an alt attribute (missing alt is an error). 2) Decorative images use alt="". 3) Informative images have descriptive text that conveys the image's meaning—not just its file name. 4) Images that are links describe the destination. 5) Images of text reproduce the text in alt. Flag any without alt, with alt matching the filename (e.g., alt="photo1.jpg"), or with generic values like alt="image" or alt="photo".

Fix

For each image missing or with poor alt text: 1) Informative images—describe what the image conveys, not just what it shows (e.g., alt="Bar chart showing 40% increase in sales Q3 2024" not alt="chart"). 2) Decorative images—add alt="" so screen readers skip them. 3) Linked images—describe the link destination (e.g., alt="Visit our Twitter profile"). 4) Images of text—copy the text verbatim into alt. 5) Complex images (charts, infographics)—provide a short alt plus a longer description via aria-describedby or a visible caption.