How to write alt text
| Image type | What to write | Example |
|---|---|---|
| Informative photo | What the image shows that matters here | Technician replacing a water heater in a garage |
| Image link or button | Where the link goes or what it does | Book an appointment |
| Image with text | The text in the image | Spring tune-up, 20% off |
| Decorative image | Nothing, with an empty alt attribute | (empty) |
The W3C's alt decision tree walks through these cases. The key question is what the image adds to the page. If it adds nothing a screen reader user needs, leave the alt text empty so screen readers skip it.
Rules of thumb
- Keep it short, one sentence at most.
- Skip "image of," since screen readers say it already.
- Describe the content, not the file name.
- Add the service and place when they matter.
- Never stuff keywords into alt text.
Google's image guidance says it uses alt text, along with the page content, to understand images. Keyword stuffing alt text makes the experience worse and can look spammy.
Good example. "Rathly team planning a client's local SEO at the Orlando office."
Bad example. "SEO agency Orlando best SEO company Orlando SEO services."
Alt text and the law
Alt text is a basic WCAG requirement, and WCAG is the standard most accessibility rules point to. Missing alt text is one of the most common accessibility failures on business sites. It is also one of the easiest to fix.
We write alt text for every image on our sites and keep it under 125 characters. Read what website accessibility means. Our web design team checks every image before launch.