Check Your PDF for Accessibility

What does the PDF accessibility checker test?

A PDF can look correct on screen and still be difficult or impossible to use with a screen reader, keyboard or other assistive technology. This checker examines the technical structure that makes the document understandable to those tools. You can begin with a private browser-based quick check, then choose the full audit when you need deeper machine-testable PDF/UA validation.

What the quick check can tell you

The quick check runs locally in your browser and does not upload your file. It is designed to answer the first questions that matter before a deeper audit:

• Is the PDF tagged? Tags provide the structural map that identifies paragraphs, headings, lists, tables and other content to assistive technology.
• Does the document declare a title and language? These properties help screen readers announce the document correctly and apply the right pronunciation rules.
• Is there enough technical structure to justify a full audit? A quick failure can often point you back to the source document before you spend time investigating individual validator findings.

What the full audit checks

The optional full audit uploads the PDF over an encrypted connection to the service in Frankfurt and runs the machine-testable PDF/UA rules with veraPDF. It checks more than 100 technical requirements covering document structure and the relationships between visible content and the tag tree. Findings can include missing or invalid tags, content that is not connected to document structure, figure and annotation problems, invalid roles, metadata failures and other issues that affect how assistive technology interprets the file.

The report translates validator findings into plain language and groups them so that you can distinguish a fundamental structural problem from a smaller metadata or tagging defect. A passing automated audit is useful evidence that the machine-testable rules were satisfied; it is not a certificate that every accessibility requirement has been met.

What automated testing cannot determine

Some accessibility questions require human judgement. Software cannot reliably decide whether alternative text communicates the purpose of an image, whether the reading order makes sense to a person, whether headings describe the real hierarchy of the document, or whether a complex table is understandable when navigated with a screen reader. Those checks remain manual even when the technical PDF/UA rules pass.

That distinction matters because accessibility is about the user experience, not just validator output. PDFChecks therefore treats automated findings and manual-review requirements separately and does not describe a successful automated check as legal compliance, certification or guaranteed accessibility.

How PDF/UA, WCAG and legal requirements fit together

PDF/UA (ISO 14289-1) is the PDF-specific accessibility standard used by the full audit. WCAG describes broader accessibility outcomes for digital content, while laws and procurement rules can reference standards such as EN 301 549. They overlap, but they are not interchangeable. A PDF/UA validator can test many structural requirements inside the file; it cannot decide every WCAG outcome or prove compliance with the European Accessibility Act or another law.

For a fuller explanation, read PDF/UA vs WCAG and the guide on how to check a PDF for accessibility.

How your PDF is handled

The quick check stays on your device. If you explicitly start the full audit, the PDF is uploaded to the EU-hosted service for analysis and the uploaded original is deleted as soon as the requested work settles. The page makes that transition explicit so you can choose whether the deeper server-side audit is appropriate for the document you are checking.

What to do after a failed check

Start with the highest-level failure. If the PDF has no useful tag structure, correcting individual lower-level findings will not make the document usable. Where possible, return to the source document, fix headings, lists, tables and image descriptions there, then export a tagged PDF again. Our Word export guide covers the common export settings, while tagged-PDF errors explained translates several frequent validator messages.

Run the checker again after making changes. The aim is not to chase a score: it is to remove technical barriers, then complete the manual review that automated tools cannot perform.