PDF/UA-2 Explained: What's New in the Accessibility Standard

PDF/UA is the ISO standard for universally accessible PDFs. The original, PDF/UA-1 (ISO 14289-1), dates from 2012 and is built on PDF 1.7. Its successor, PDF/UA-2 (ISO 14289-2), was published in 2024 and is built on PDF 2.0. As accessibility laws like the European Accessibility Act raise the stakes, more teams are asking which version they should target.

Why a second version?

PDF 2.0 brought improvements to how structure is described, and PDF/UA-1 could not use them because it was tied to PDF 1.7. PDF/UA-2 takes advantage of the newer format:

• A richer tag set. PDF 2.0 introduced new structure elements (such as Title, FENote for footnotes and endnotes, Aside, and DocumentFragment) that describe content more precisely.
• Namespaces. Tags can belong to defined namespaces, including MathML for mathematics, so equations can be truly accessible instead of relying on alt text.
• Better handling of links, notes and annotations, with clearer rules for how they relate to the structure tree.
• Alignment with the "Well-Tagged PDF" specification (WTPDF), which the PDF Association published alongside PDF/UA-2 to define tagging that serves both accessibility and content reuse.

What WTPDF adds

WTPDF describes PDFs whose tags are good enough to reuse content reliably, whether for a screen reader, reflowing on a phone, or extracting into another format. It is closely aligned with PDF/UA-2. This matters beyond accessibility: well-tagged PDFs are also the ones that AI tools and data extraction read correctly. See how to make PDFs readable by AI agents.

What did not change

The core principles are the same:

• All meaningful content is tagged; decoration is an artifact.
• Reading order is logical.
• Images have alternative text.
• Tables have marked headers.
• The document declares its language and title.

If you already produce good PDF/UA-1 files, you have the habits PDF/UA-2 needs.

Should you switch now?

For most organisations, PDF/UA-1 is still the practical target in 2026:

• Many authoring tools still export PDF 1.7, and PDF/UA-1 validators are more mature.
• Laws and procurement rules usually ask for "accessible" or reference WCAG, not a specific PDF/UA version.
• Assistive technology support for new PDF 2.0 structure elements is still catching up.

Consider PDF/UA-2 if you publish mathematical or scientific content (MathML support is a real gain), if your toolchain already exports PDF 2.0, or if you are building a new document pipeline from scratch.

How to tell which version a PDF claims

Open Document Properties and look at the PDF version and the conformance claims in the metadata. A file claiming PDF/UA-2 must be PDF 2.0. A claim is not proof; run it through a validator. See PDF 1.7 vs PDF 2.0.

Takeaway

PDF/UA-2 is a modernised accessibility standard for a modernised PDF format. The principles are unchanged, the vocabulary is richer, and maths finally gets first-class support. Keep producing solid PDF/UA-1 today, and plan for PDF/UA-2 as your tools adopt PDF 2.0. For the legal context, see the European Accessibility Act checklist.