Alt text describes an image for people using screen readers and for search engines. Images without it are an accessibility problem as well as an SEO warning.
Why Joomla sites get it
Joomla asks for alt text in two places: the Image Description (Alt Text) fields for an article’s intro and full-text images, and the image dialog in the editor. Both are easy to skip, and images pasted into the editor often arrive with none. For an image that is purely decorative, tick No Description so Joomla writes an empty alt attribute on purpose.
Fix it by hand
- Open the article. For the intro and full-text images, fill in Image Description (Alt Text) on the Images and Links tab.
- For images in the text, select each image in the editor and add a description in its image properties.
- Describe what the image shows and why it is there, in a few words.
Fix it with MetaGen
Good alt text needs a person’s judgement, so MetaGen doesn’t invent it. The Missing image alt text row lists the articles with images that have none, with a link to edit each one.
MetaGen is free for Joomla 5 and 6. See all the SEO warnings MetaGen checks.