Alt Text Validation
Alt text validation checks that images have appropriate, descriptive alternative text — conveying the image's purpose or content to users relying on a screen reader — and that purely decorative images are correctly marked to be skipped rather than announced with unhelpful or redundant text.
Good alt text describes function or content concisely — "Submit payment button," not "blue rectangle image123.png" — and automated scanners can reliably catch missing alt attributes entirely, but can't judge whether the text present is actually meaningful, which still requires human review.
A common, easy-to-miss failure mode is decorative images given unnecessary alt text that clutters the screen reader experience — a background pattern or spacer image should have an empty alt attribute (`alt=""`) so it's skipped silently, rather than being announced and adding noise to every page load for screen reader users.
