An alt attribute is a short description of an image on a website. It sits in the HTML and tells search engines and screen readers what the image shows.
If an image cannot load, the alt text is often displayed instead.
Why do alt attributes matter?
Alt attributes help search engines understand images, since Google cannot interpret a picture the way a person does.
They also improve accessibility, because screen readers can read the description aloud. That lets people with visual impairments understand what is on the page.
A good alt attribute should:
- describe what is actually visible
- stay reasonably short
- avoid unnecessary keyword repetition
For example:
- Poor: ”image123”
- Good: ”red women’s running shoe on a white background”
Why the alt attribute matters for SEO
Alt attributes can help you become more visible in Google image search. They support search engines in connecting an image to the content around it.
For online shops, blogs and local websites in particular, well-optimised images can bring additional traffic.