This translation has not been editorially reviewed yet. The German version is authoritative. Deutsche Fassung →
Image alt text from an SEO perspective: what it does and doesn't do
Alt text is the most important signal for what an image shows — for screen readers and for image search alike. The check verifies its presence; whether the text captures the image's content is decided by a human.
- From an SEO perspective, alt text is the only reliable text source for an image. Anyone who leaves it out gives up image search as an access path.
- The temptation to stack search terms in there is old, and it does double harm: search engines recognise it, and a screen reader reads the list out loud. What's spam to one is noise to the other.
- The accessibility-law part of the same topic is on the alt-text article — that covers empty alt text for decorative images, and why an automated test can't judge quality.
