Free tools · Checker
Alt text checker
Alt text is what a blind visitor gets instead of your image, and most of it fails in the same five ways. Paste yours and catch the filename reads, the “image of” prefixes, and the paragraphs pretending to be labels, before a screen reader announces them.
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These are the mechanical checks, which are the same red flags we screen for first on an audit before anybody reads a word for meaning. The rule underneath all of them is 1.1.1 Non-text Content, and it asks for a text alternative that serves the same purpose, which is a question about your page rather than about your string. So this reads only what you paste. It never sees your markup, which means an image with no alt attribute at all is invisible here and turns up in the free scan instead. When you are ready to write the replacement, the wording is covered in how to add alt text to an image and the same-purpose test in alt text that serves the same purpose.
What it checks
Alt text that says nothing
A single word like “image” or a string of punctuation leaves a screen reader user with nothing, and bulk-imported content is full of both.
Alt text that is a filename
IMG_4021.jpg read aloud is worse than silence, and bulk imports produce it by the hundred.
Placeholder wording
“image”, “photo”, “graphic” and similar describe the medium rather than the content.
Very long alt text
Alt is announced in one run with no pauses. Past a couple of sentences the information stops arriving.
What it cannot tell you
- Whether the alt text is correct. “A dog” on a photograph of a cat passes every automated check there is.
- Whether an image should have been decorative instead. That is a judgment about what the image is doing on the page, not about the markup.
- Anything about your actual page. This reads the text you paste rather than your markup, so a missing alt attribute is found by the free scan and not here.
Where to go next
- Does this image need alt text?Work out which of your images are decorative before writing anything.
- How to write alt textWhat to say once you know the image carries meaning.
- 1.1.1 Non-text ContentThe rule itself, and the most-cited one in complaints.
- Image techniquesThe documented ways to satisfy it, including the awkward cases.
The half no tool can check
Mechanics are checkable and meaning is not. “Golden retriever puppy” passes every rule here and still fails if the image is actually your return-policy diagram. Whether alt text serves the image's purpose is judged by humans, and ours do it on every audit, image by image.