Written by the AX4E accessibility team. Checked against the primary sources listed at the end of this page (W3C, U.S. Department of Justice, ISO and others). Last reviewed November 4, 2026. Read how we write and review guides in our editorial standards.
WCAG: the content standard
The Web Content Accessibility Guidelines apply to digital content in general, including documents. When a law, policy or contract says documents must be accessible, it almost always points to WCAG 2.1 or 2.2 Level AA. WCAG asks outcome questions: Is there a text alternative? Is the reading order meaningful? Is the contrast sufficient? Can a form be completed by keyboard?
PDF/UA: the file-format standard
PDF/UA (Universal Accessibility) is an ISO standard, ISO 14289, that defines technical requirements for an accessible PDF file: how tags, structure, fonts, metadata and other internals must be set up so assistive technology can interpret the document reliably.
- PDF/UA-1 (ISO 14289-1) is the version most tools and checkers support today.
- PDF/UA-2 (ISO 14289-2, published 2024) builds on the newer PDF 2.0 format and is aligned with the PDF Association's Well-Tagged PDF guidance.
How they fit together
| WCAG | PDF/UA | |
|---|---|---|
| Published by | W3C | ISO |
| Applies to | All digital content | PDF files only |
| Focus | Can people use the content? | Is the file built correctly? |
| Typically required by | Laws, policies, contracts | Technical specs, some contracts |
| Checked by | Automated tools plus human review | Automated checkers plus human review |
A file can pass a PDF/UA checker and still fail people, for example if the alternative text is wrong or the reading order is technically valid but confusing. A file can also be readable but fail PDF/UA on technical details. The goal is both: content that meets WCAG, in a file that follows PDF/UA.
What to ask a vendor for
- Conformance to WCAG 2.1 or 2.2 Level AA for the content.
- Alignment with PDF/UA for the file structure.
- Both an automated check and a manual check with assistive technology.
- A record of what was checked and fixed for each document.
Common questions
Is PDF/UA required by law?
Most U.S. laws and regulations reference WCAG rather than PDF/UA. PDF/UA is a technical standard often used to meet WCAG for PDFs and is sometimes named in contracts and specifications.
What is the difference between PDF/UA-1 and PDF/UA-2?
PDF/UA-1 is based on earlier PDF versions and is widely supported. PDF/UA-2, published in 2024, is based on PDF 2.0 and adds updated requirements. Tool support for PDF/UA-2 is still growing.
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