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Alt Text Checker

Find images with missing, empty, filename-based or overlong alternative text.

Alt text fails in predictable ways: a missing attribute, an empty one on a meaningful image, the filename copied in, a redundant "image of" prefix, or a description so long that screen readers truncate it. This checker finds all five in pasted HTML and explains what each image needs instead.

Runs in your browser
Checks
Missing, wrongly empty, filename-as-alt, redundant prefix and overlong descriptions
WCAG criterion
1.1.1 Non-text Content, Level A
Privacy
Runs entirely in your browser — nothing is uploaded
Cost
Free, unlimited, no sign-up

Frequently asked questions

When should alt text be empty?

When the image adds nothing a listener would miss — a decorative divider, a background flourish, or an icon beside text that already says the same thing. Use alt="" with role="presentation" so screen readers skip it entirely, rather than omitting the attribute.

How long should alt text be?

One clear sentence is usually right. Some screen readers truncate around 125 characters, so if a description genuinely needs more, put it in the surrounding text where every reader benefits.

How to use the alt text checker

  1. 1Enter or paste your html.
  2. 2Set the flag alt text longer than.
  3. 3The result appears immediately — copy or download it.

Embed this tool

Put the working alt text checker on your own site. It runs in your visitors' browsers exactly as it does here — free, no account, nothing uploaded.

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