How to check if a PDF is accessible

The four ways to check

Acrobat Pro’s Accessibility Checker

In Acrobat Pro, go to All tools → Prepare for accessibility → Check for accessibility, choose your options and select Start Checking. The results panel marks each rule Passed, Failed, Needs manual check or Skipped by user (Adobe help). Use the ⋯ menu on a failed rule to Fix it, Explain it or Check again.

Know the limits: Adobe says Logical Reading Order has to be verified by hand, and the checker can’t tell essential content from decoration, so some flags won’t matter and some real problems won’t show. A clean Acrobat report is a good sign, not proof of full PDF/UA conformance. It also checks one file at a time.

PAC

PAC, from the Swiss foundation “Access for all” and now axes4, is the free checker most remediation professionals use. You drag a file in and get a summary or a detailed report against PDF/UA and WCAG requirements. Its screen-reader preview shows the reading order and structure a screen-reader user will get. PAC runs on Windows, and the current release (PAC 2026) adds AI-assisted checks to cut down manual testing.

Because PAC follows the PDF/UA failure conditions closely, it flags things Acrobat lets through, such as untagged content outside the structure tree or a missing PDF/UA identifier. Expect a stricter result.

veraPDF

veraPDF is an open-source validator that covers every part of PDF/A and PDF/UA. It runs on Windows, macOS and Linux, and it has a command-line mode, which makes it the right pick for automated pipelines (for example, validating every PDF your CMS publishes). It tests only the machine-checkable rules, so treat a pass as “technically well-formed” rather than “accessible”.

Checking hundreds of PDFs

A city website or school district can easily have thousands of PDFs. Opening each one in Acrobat or PAC doesn’t scale, and you don’t need to: most files fall into a few buckets (scanned images with no text, untagged, tagged with problems, nearly fine). Triage first:

1. Export the folder, or download the PDFs from your site.
2. Run them through PDF Triage. It runs in your browser, so nothing is uploaded, and it sorts every file into scanned, untagged, needs fixes, quick fix and passes.
3. Archive or remove what you don’t need (ADA Title II has an archived-content exception; see the Title II guide).
4. Send scanned and untagged files to remediation (budget them with the cost calculator), fix the quick ones yourself, and spot-check the “passes” bucket in PAC.

What no tool can check for you

• Reading order that makes sense, not just order that exists.
• Alt text that describes the image’s purpose. Tools can only see whether alt text is present.
• Contrast and color used to convey meaning.
• Table meaning: correct header cells and scope on complex tables.
• Link and heading text that makes sense out of context.

The University of Washington’s guide recommends the same mix: automated checks, then a manual review. Our 14-point checklist splits the checks into machine and human ones.

Frequently asked questions