Conflicts when creating accessible PDF documents (3/3)

Accessible PDF documents

Accessibility and PDF/UA​

PDF accessibility is a broad topic that also includes practical conflicts.

In both physical and digital contexts, accessibility is complex and must be viewed from multiple angles. An environment is considered accessible when all people can use it equally and without assistance, including people with disabilities.

For PDFs, the question "Can PDF documents really be accessible?" can clearly be answered with yes, provided that creators understand core requirements and avoid common pitfalls during creation and validation.

The persistent myth that accessible PDFs do not exist is outdated. At the same time, the topic was neglected for years and still requires further development in practice. A PDF/UA-compliant file does not automatically guarantee full accessibility in every real-world use case.

PDF and accessibility: what conflicts exist and why?​

One source of conflict is the original goal of PDF: preserving visual appearance. PDF originated from print-oriented technology, not from structure-first formats like XML. As a result, visual fidelity was prioritized, while semantic structure was often secondary.

This creates barriers for blind users who rely on structured content. For screen readers, documents need tags and structure elements such as headings and paragraphs. (See part 2 for fundamentals.)

Common problem: protected PDF documents​

A common issue is that some PDFs cannot be made sufficiently accessible, for example when content is raster-only, multi-column structures are ambiguous, character encoding is problematic, or text access is restricted.

Conflicts in accessibility validation​

Additional issues may arise during validation. Some files can be incorrectly classified as accessible. Therefore, do not rely solely on fully automated checks.

Important points to verify during checks​

  • If reflow is used, verify that no display errors occur.
  • Tags used for structure must be semantically and syntactically correct.
  • Even with Matterhorn protocol and PAC checks, some criteria require human judgment.
  • EN 301549 can include requirements that are not fully covered by PDF/UA, so check those explicitly as well.

Which standards should be considered for PDF validation?​

Accessibility validation should combine several perspectives. Besides general usability, use PDF/UA, WCAG, EN 301549, and ISO 14289 as key references.

A practical baseline is ISO 14289 plus PAC checks from the PDF/UA Foundation. This supports PDF/UA and WCAG conformity checks, but a manual review with screen readers is still essential.

Conclusion: accessible PDF documents​

Accessible documents benefit many groups, including non-native speakers and users with limited literacy. The myth that PDF cannot be accessible is false. At the same time, accessibility capabilities in PDF are still underused in practice.

Tagged PDF and PDF/UA have evolved over many years (including PDF/UA-2 based on PDF 2.0). The direction is clear: PDFs can and should be made accessible.