Alt text writer and checker
Turn a few answers into alt text that follows the rules, or paste alt text you already have and see what is wrong with it. Nothing is uploaded, and it never sees the image — it works from what you tell it.
The attribute
alt=""- Fix: Empty. A meaningful image with no alt text is invisible to anyone using a screen reader, and to every crawler.
The rule underneath
It is for people, and search engines happen to read it
Alt text exists so that somebody who cannot see an image still gets what it was doing there. That is the whole specification. Every other benefit — image search, a page that still makes sense when the picture fails to load, a crawler that understands the content — follows from doing the first thing properly.
Which is why a keyword list is treated here as a defect rather than a shortcut. Read aloud, it is nonsense. Somebody has to sit through it. And search engines have treated stuffed alt text as a negative signal for a very long time, so it does not even work.
Questions
The things people ask first
Does it look at my image?
No, and nothing is uploaded. It cannot see a picture it never received, so it asks you what is in the image and turns your answers into a sentence that follows the rules. A tool that claimed to describe a photo without being given one would be guessing.
What should alt text actually say?
What somebody would miss by not seeing the image, in the context of the page it is on. The same photograph on a news story and on a product page needs different alt text, because a different part of it is load-bearing.
Should it start with “image of”?
No. A screen reader already announces that it is an image, so the phrase is read out twice. Start with the subject.
What about decorative images?
They take an empty alt attribute — alt="" — which is not the same as leaving the attribute off. Present and empty tells a screen reader to skip it. Missing entirely makes some screen readers read the filename out loud instead.
The image is a link. Does that change anything?
Completely. The alt then becomes the link's accessible name, so it has to describe where the link goes, not what the picture shows. “Smiling woman” tells somebody navigating by links nothing about whether to follow it.
Is there an SEO benefit?
Yes, as a side effect. Search engines read alt text and use it, particularly in image search. But every rule here serves the accessibility purpose first, and anything that helps ranking at the expense of a listener — keyword lists, stuffed brand names — is flagged as a defect, because to somebody using a screen reader that is exactly what it is.
How long should it be?
Long enough to carry the meaning and no longer. Past roughly 125 characters, ask whether the detail belongs in the surrounding text or a caption instead, where everybody gets it rather than only the people who cannot see the image.