Tools › Documents
PDF accessibility checker
Check a PDF for tags, document language, title, alt text, embedded fonts, form field labels, link text and scanned pages, with a plain-English fix for each problem.
How it works
- Nibbo opens the PDF structure and runs the checks that software can decide: is it tagged, is a language set, does every figure have alt text, are fonts embedded, do form fields have a tooltip name.
- Each result is mapped to the WCAG 2.2 success criterion and the PDF/UA-1 clause it comes from.
- Pages with images but no text are flagged as probably scanned, which screen readers can’t read at all.
Questions
Does passing mean my PDF is accessible?
It means the machine-checkable basics are in place. Whether alt text is meaningful and the reading order makes sense still needs a person, ideally with a screen reader.
How do I fix an untagged PDF?
Export again from the source with tagging on: in Word, File › Save As › PDF › Options › “Document structure tags for accessibility”. Tagging an existing PDF by hand needs Acrobat Pro or a similar editor.
Is the file uploaded?
No. The check runs in a background thread in this tab.