Image Alt Text Checker
Alt text describes an image for people who cannot see it and for search engines that index images. This checker lists every image on a page with its alt text and a verdict: missing alt attributes, empty alt text on images that are the only content of a link, alt text that is just a file name, phrases like “image of”, descriptions that are too long and the same text repeated on many images. Decorative images with alt="" are recognised as correct.
- Encrypted connection
- No sign-up
- Free to use
How to use Image Alt Text Checker
- Enter a page URL (or paste its HTML).
- Click “Check alt text”.
- Start with the images marked red.
- Write a short description of what each image shows.
Image Alt Text Checker features
Missing alt
Images without the attribute.
Linked images
Empty alt where the image is the link.
Quality checks
File names, “image of”, length, repeats.
Decorative images
alt="" recognised as intended.
Image buttons and maps
input type=image and area elements.
Paste mode
Analyse HTML you paste, e.g. a staging page.
When to use Image Alt Text Checker
- Accessibility reviews against WCAG 1.1.1.
- Improving image search visibility.
- Checking CMS uploads that use file names as alt text.
- Reviewing product pages before launch.
Image Alt Text Checker FAQ
What is good alt text?
A short sentence that says what the image shows or does in this context, for example “Red road bike leaning on a wall”. Leave out “image of” – screen readers already say it is an image.
When should alt be empty?
When an image is purely decorative and adds no information. Use alt="" so screen readers skip it; leaving the attribute out makes some read the file name.
How long can alt text be?
There is no hard limit, but about 125 characters is a common guideline. Put longer explanations in a caption or the surrounding text.
Does alt text help SEO?
Yes. Search engines use it to understand images and the page, and it is the anchor text when an image is a link.
Should alt text contain keywords?
Only when they describe the image naturally. Alt text is for people first; stuffing it with keywords hurts accessibility.
Images described properly
Screen-reader users hear alt text in place of an image. Without it they may hear a meaningless file name, or nothing at all on a linked image, which leaves them guessing where the link goes. That is why missing alt text is one of the most common accessibility failures found in audits.
Search engines read alt text too, especially for image search, where it is one of the main signals besides the file name and the surrounding text. Descriptive, honest alt text helps both audiences; stuffing it with keywords helps neither.
The checker reads the HTML of the page, so images added later by JavaScript are not included.
Alt text describes an image for people who cannot see it and for search engines indexing images. The checker lists every image with its alt text and a verdict, so missing or poor descriptions stand out.
It flags missing alt attributes, empty alt text on images that are the only content of a link, alt text that is just a file name, phrases like “image of” and very long descriptions. Decorative images should have an empty alt attribute (alt="") so screen readers skip them.
Good alt text describes what the image shows in its context in a sentence or less. For images that contain text, include that text.