How Accessible are your PDF Files?

Why accessibility cannot be assumed and how PDFs are actually evaluated.

PDF accessibility testing is the only way to confirm whether a document is usable by assistive technologies, regardless of how accessible it may appear visually.

This article explains how PDF accessibility is evaluated and why accessibility must be verified rather than assumed.

Why accessibility is often assumed

PDFs that appear clean, well-organized, and professional are often assumed to be accessible.

Common assumptions include:

  • The document looks structured

  • Headings appear visually correct

  • An accessibility checker reports no errors

  • The PDF was exported from a modern authoring tool

Unfortunately, none of these factors guarantee accessibility.

Why visual review is not enough

Accessibility barriers are often invisible to sighted users.

Issues such as:

  • Incorrect reading order

  • Missing or incorrect tags

  • Improper heading hierarchy

  • Decorative content exposed to screen readers

cannot be reliably detected through visual inspection alone.

A PDF can look perfect and still be unusable for assistive technology users.

The limits of automated accessibility checkers

Automated tools are useful, but they only identify certain types of issues.

They cannot determine:

  • Whether reading order is logical

  • Whether headings reflect document structure

  • Whether alternative text is meaningful

  • Whether content makes sense when read aloud

As a result, PDFs often pass automated checks while still failing real-world accessibility requirements.

How PDF accessibility is evaluated in practice

PDF accessibility is evaluated through a combination of:

  • Technical inspection of tags and structure

  • Review of reading order

  • Manual checks for content meaning

  • Assistive technology testing

This process verifies whether the PDF is usable by screen reader and keyboard users, not just whether it meets surface-level criteria.

What standards PDF accessibility is evaluated against

PDF accessibility is typically evaluated using:

Together, these provide a framework for determining whether a PDF is both accessible and technically compliant.

Common PDF accessibility failures

Accessibility evaluations frequently identify issues such as:

  • Missing or incomplete tagging

  • Incorrect reading order

  • Headings styled visually but not semantically

  • Inaccessible tables or forms

  • Missing document language or metadata

These issues often exist even in PDFs believed to be accessible.

Why accessibility must be verified, not assumed

Accessibility is a functional requirement, not a visual one.

Without verification:

  • Accessibility claims cannot be substantiated

  • Compliance risk remains

  • Users may encounter barriers

Verification ensures that accessibility exists in practice, not just in appearance.

Conclusion

PDF accessibility cannot be determined by appearance or automated checks alone. It must be evaluated through structured review and testing.

Organizations that rely on PDFs for public, customer-facing, or regulated use should ensure that accessibility is verified rather than assumed.

Accessibility Testing Note

PDF accessibility is commonly verified through structured testing that includes technical review and assistive technology testing.