Alt Text Checker

Alt text (alternative text) is a text alternative in an image's alt attribute. It communicates an image's purpose to people using assistive technology and can help search engines understand image content. The checker cannot decide whether text is an accurate description without seeing the image and page context.

The tool scans every <img> tag in your HTML and checks for four things: missing alt attributes, empty (decorative) alt text, suspicious alt text that looks like filenames or generic placeholders, and alt text that passes all quality checks. It also flags images missing a src attribute and reports the line number for each finding.

No. An empty alt="" attribute is the correct way to mark an image as purely decorative. It tells screen readers to skip the image entirely, which is the desired behavior for spacer GIFs, decorative dividers, and images whose meaning is already conveyed by adjacent text. The checker categorizes these as "Decorative" rather than as errors.

Alt text is flagged as suspicious when it exists but appears low-quality. This includes text that simply repeats the filename, uses generic words like "image" or "photo," contains file extensions such as .jpg or .png, starts with camera-generated prefixes like "IMG*" or "DSC*", looks like a random hash, or is either too short (under 4 characters) or too long (over 125 characters). These are common signs that the alt text was auto-generated or copied without thought.

The analysis runs in your browser without uploading the input through the tool. Avoid using a shared or untrusted device for sensitive source code.

Write a concise alternative that conveys the image's purpose in context. There is no universal character limit that makes alt text correct; charts or complex images may need a longer explanation elsewhere on the page. The checker's length warnings are only heuristics.

Descriptive alt text can help search engines interpret images, but it does not guarantee image-search visibility or higher rankings. Write for the image's purpose and users; do not add keywords that do not accurately describe it.

WCAG 2.1 Success Criterion 1.1.1 (Non-text Content, Level A) requires text alternatives for non-text content, with exceptions and specific requirements depending on purpose and context. An empty alt="" is appropriate for decorative images. This checker alone cannot establish WCAG conformance or legal compliance.

This tool scans the HTML you paste or upload, so it checks one page or HTML fragment at a time. To audit a full website, paste the HTML of each page individually, or save each page as an .html file and drop them in one at a time. For large multi-page audits, you can export a Markdown report per page and combine them.

It depends on each image's purpose in context. A repeated image may need the same alternative, different text, or an empty alt="" if decorative. The checker does not identify duplicate descriptions or decide which treatment is appropriate.

The scanner notes some ARIA attributes, but it does not compute the accessible name or test how assistive technology will expose the image. Review the rendered element and its purpose; the checker focuses on the alt attribute and is not a conformance test.

Yes. After scanning, use the Copy report or Download report buttons to export a complete Markdown audit file. The report includes a summary of all statistics plus a detailed breakdown of every image with its line number, status, source, alt text, and any issues found. This is ideal for sharing with your team, attaching to a pull request, or delivering to a client.