Images
Every image must expose the right text alternative for its purpose, or be hidden if it is purely decorative. The test is about meaning, not just the presence of an alt attribute.
What to test
- Informative images have alt text conveying their meaning, not their file name.
- Decorative images are hidden from assistive tech (empty alt="" or aria-hidden).
- Functional images (icon buttons, logo links) describe the action or destination.
- Complex images (charts, diagrams) have an extended description nearby or linked.
- Text baked into images is avoided, or duplicated as real text.
How to test
- 1Turn images off (or use a text-only view) and confirm the page still makes sense.
- 2Navigate image-by-image in a screen reader (NVDA/JAWS “g”) and listen to each announcement.
- 3Inspect the accessible name in the browser's accessibility tree.
- 4For each image ask: does the alt convey what a sighted user gets, no more, no less?
Common failures
- alt="image", alt="logo", or the raw filename.
- Decorative images given descriptive alt that adds noise.
- Icon-only buttons with no accessible name.
- Charts with alt="chart" and no underlying data description.