What alt text is for
Alt text is the short description in an image's alt attribute. Screen readers read it aloud to people who cannot see the image, browsers show it when an image fails to load, and search engines use it to understand what the image shows. Good alt text serves people first. The search benefits follow.
How to write good alt text
- Describe what matters on this page. The same photo of a laptop bag needs different alt text on a product page (color, material, style) and on a blog post about remote work (the scene it shows).
- Keep it short. Aim for about 125 characters or fewer. Long descriptions are tiring to listen to.
- Skip "image of". Screen readers already announce that it is an image.
- Include text in the image. If a graphic shows a headline, a price or a quote, put that text in the alt text.
- Be factual. Describe what is visible. Do not guess who people are or how they feel.
Examples
- Too thin: alt="bag"
- Keyword stuffed: alt="leather bag laptop bag cheap leather laptop bag buy"
- Useful: alt="Brown leather laptop bag with a brass buckle and padded shoulder strap"
Decorative images and links
Images that add nothing to the content, such as background patterns or dividers, should have an empty alt attribute (alt="") so screen readers skip them. If an image is a link or a button, the alt text should say where it goes or what it does, such as "Download the price list".
Alt text and SEO
Search engines use alt text, file names and the surrounding text to understand images. Use a keyword only when it accurately describes the image, and never stuff phrases. Descriptive file names, such as brown-leather-laptop-bag.jpg, help too.
Check before you publish
AI can misread small details, brands and text in images. Read each description next to the image and correct anything that is not accurate before you add it to your site.