Image alt text: how to write it for SEO and accessibility

Alt text is a short description of an image, stored in the image's alt attribute. Screen readers read it aloud for blind and low-vision visitors, browsers show it when the image fails to load, and search engines use it to understand the picture.

How to write good alt text

• Describe what matters in the image, in the context of the page.
• Be brief: one sentence, usually under 125 characters.
• Don't start with "image of"; screen readers already say it's an image.
• Include a keyword only if it fits naturally.
• Text in an image? Put that text in the alt.
• Decorative images (dividers, background shapes) get alt="".

How to add it

• WordPress: click the image → Alt text in the block settings, or in the Media Library.
• Shopify: product media → click the image → Add alt text.
• Wix: image settings → What's in the image?
• Squarespace: image block → Image alt text / filename field, depending on the block.

Bonus: the title attribute

The title attribute shows a tooltip on hover. It's optional and not a replacement for alt text.

The SEO audit lists every page with images that have no alt attribute at all. Then check the accessibility basics for links and forms.