PDF/UA — where UA stands for Universal Accessibility — is the ISO standard (ISO 14289) that defines what a fully accessible PDF looks like. It goes beyond general accessibility best practices to specify precise technical requirements that PDF viewers, assistive technologies, and authoring tools must meet. If you distribute PDFs to the public or within regulated industries, PDF/UA is increasingly the standard you need to know.
What PDF/UA Requires
PDF/UA is built on top of tagged PDF — a document must be tagged before it can claim PDF/UA conformance. But PDF/UA adds requirements beyond basic tagging:
- All content must be tagged: every element on every page must have a tag — no untagged content is permitted. Purely decorative elements must be explicitly marked as artifacts so assistive technology skips them.
- Images must have alternative text: every non-decorative image requires a meaningful alt text description. Generic descriptions like "image" or "photo" don't meet the standard — the alt text must convey what the image communicates.
- Logical reading order: the tag order must match the logical reading sequence — content must be encountered in the order a reader would naturally read it, not in the order it was placed on the page.
- Fonts must be embedded and mappable: all fonts must be embedded with proper Unicode mapping so text can be reliably extracted and read by assistive technology.
- Document language must be specified: the document's primary language must be declared in the metadata so screen readers use the correct pronunciation rules.
- Security must not block assistive technology: PDF security settings that block content copying also block screen readers — PDF/UA requires that security permissions allow assistive technology access.
PDF/UA vs WCAG: Different but Related Standards
WCAG (Web Content Accessibility Guidelines) is the accessibility standard for websites and web content. PDF/UA is the accessibility standard for PDF documents. They address different formats but share common goals — both require perceivable content, operable navigation, understandable structure, and robust compatibility with assistive technology.
Many accessibility regulations reference WCAG for web content and either PDF/UA or Section 508 technical standards for PDF documents. In practice, a PDF that meets PDF/UA requirements also satisfies most PDF-related WCAG success criteria. The two standards are complementary rather than competing.
Who Needs to Follow PDF/UA
PDF/UA compliance is explicitly required or strongly expected in several contexts:
- Government agencies: US federal agencies under Section 508, EU public sector bodies under the Web Accessibility Directive, and equivalent regulations in other countries require accessible PDFs for public-facing documents.
- Education: universities and schools distributing course materials, syllabi, and official documents have accessibility obligations under disability discrimination legislation in most jurisdictions.
- Healthcare: patient communications, consent forms, and health information must be accessible under various healthcare accessibility regulations.
- Financial services: customer-facing PDFs including statements, contracts, and disclosures are increasingly subject to accessibility requirements under financial services regulations.
Private organizations aren't always legally required to follow PDF/UA, but doing so reduces legal risk, improves the experience for users with disabilities (estimated at 15-20% of the population), and demonstrates genuine commitment to PDF Accessibility rather than minimum compliance.
How to Check PDF/UA Conformance
Adobe Acrobat Pro's Accessibility Checker (Tools > Accessibility > Full Check) tests for PDF/UA compliance and lists specific issues. The tool categorizes failures by type — missing alt text, untagged content, logical structure problems — and links to guidance on fixing each one.
PAC (PDF Accessibility Checker) is a free tool specifically designed for PDF/UA validation — more detailed than Acrobat's built-in checker and freely available from the PDF/UA Foundation. It produces a comprehensive report categorizing all failures and warnings against the PDF/UA standard requirements. For organizations that need to verify PDF Standard compliance across many documents, PAC is the reference tool.