What is alt text and why does every image need it?
Alt text is a short description of an image in the page code. Screen readers read it aloud to blind and partially sighted visitors, Google Images indexes it, and it appears in place of the image if the file fails to load. Describe what the image shows and why it is there. Purely decorative images should have an empty alt attribute so screen readers skip them. Missing alt text is the most common accessibility failure on the web.
Why it matters
Around two million people in the UK live with sight loss, and a site whose photos are announced as "image" or "IMG_2041.jpg" tells them nothing. It is also a legal matter: the Equality Act requires reasonable adjustments, and the accessibility standards that flow from it start with alt text. For search, alt text is the main way Google understands what a picture shows, and the only way it ranks in image search.
Writing good alt text
- Say what the image shows and why it is on the page: "Fitted kitchen in oak with a central island" rather than "kitchen".
- Keep it to a sentence; screen readers read it in full.
- Do not start with "image of" or "picture of"; the screen reader already says that.
- If the image is a link, describe where the link goes.
- If the image is purely decorative, a swirl or a spacer, use alt="" so it is skipped.
- If the image contains text, put the text in the alt.
How to check
Our check counts images on your home page with no alt attribute at all. Browser extensions such as WAVE list every image with its alt text so you can judge the quality, not just the presence.
How to fix it
On WordPress, every image in the media library has an "Alternative text" field, and the value is used wherever the image is inserted. Work through the library, or at least the images on your main pages. Themes and page builders sometimes have their own alt fields for hero images and backgrounds; check those too. Make writing the alt text part of uploading any new image.
Not sure how your own site does on this? Run the free check: it takes about twenty seconds and reports on this and thirty other things.