What Is PDF/UA and Do I Need It?
PDF/UA (ISO 14289) is the international standard for accessible PDFs. Learn what it requires, who needs it, and how to validate your documents against it.
PDF/UA (Universal Accessibility) is the international standard for accessible PDF documents, formally known as ISO 14289. If your organization publishes PDFs that must be accessible to people with disabilities — particularly if you work in higher education or government — then yes, you almost certainly need it. PDF/UA provides a clear, testable set of requirements that ensure PDFs work reliably with assistive technologies like screen readers, making it the definitive benchmark for PDF accessibility compliance.
What Does PDF/UA Stand For?
The "UA" stands for Universal Accessibility. The standard was first published in 2012 as ISO 14289-1 (PDF/UA-1) and defines the technical requirements a PDF must meet to be considered accessible. Think of it as the PDF-specific companion to WCAG: while WCAG applies broadly to digital content including PDFs, PDF/UA translates those principles into concrete, machine-verifiable rules for the PDF file format.
What Does PDF/UA Require?
PDF/UA is built on the concept of tagged PDFs — documents that contain a logical structure tree describing the content's meaning and reading order. A PDF/UA-conforming document must meet several key requirements:
Structure Tags
Every piece of meaningful content must be tagged with the appropriate structural element. Headings must be marked as headings, paragraphs as paragraphs, lists as lists, and tables as tables. Decorative elements must be marked as artifacts so assistive technologies can skip them. There is no room for ambiguity — if content is untagged, the document fails.
Logical Reading Order
The structure tree must reflect a logical reading order that makes sense when content is consumed linearly. This is particularly important for multi-column layouts, sidebars, and documents with complex visual arrangements. A sighted reader might scan the page visually, but a screen reader follows the tag order, so it must be coherent.
Alternative Text
All images, figures, and non-text content must have appropriate alternative text descriptions. Charts need meaningful summaries. Decorative images must be marked as artifacts rather than given empty alt text. The standard is specific: alt text must convey the same information the visual element provides.
Metadata and Language
The document must declare its primary language, and any passages in a different language must be tagged accordingly. Title metadata must be present, and the document should be set to display the title (not the filename) in the title bar. These details matter for screen readers that need to switch pronunciation rules between languages.
Font and Character Requirements
All fonts must be embedded, and every character must map to Unicode. This ensures that text can be extracted, searched, and read aloud accurately. Scanned documents that are essentially images of text fail this requirement unless they have been properly OCR-processed and tagged.
Table Structure
Data tables must include proper header cell markup so that screen readers can associate data cells with their corresponding headers. Complex tables with merged cells or multiple header levels require additional structural markup.
Who Needs PDF/UA?
Universities and Higher Education
With the DOJ's ADA Title II deadline requiring digital accessibility compliance, universities are under increasing pressure to ensure all published materials — syllabi, course packets, research papers, administrative forms — meet accessibility standards. PDF/UA provides the clearest technical benchmark for PDF documents. If your institution is working toward WCAG 2.1 AA compliance, PDF/UA conformance for your PDFs is the most defensible approach.
Government Agencies
Many countries mandate accessible document publication. Section 508 in the United States, EN 301 549 in the European Union, and similar regulations in Canada and Australia all point toward PDF/UA as the technical standard for accessible PDFs. Government procurement requirements increasingly reference it directly.
Publishers and Content Creators
Any organization that distributes PDFs to the public — reports, forms, whitepapers, manuals — benefits from PDF/UA conformance. It reduces legal risk, broadens your audience, and demonstrates a genuine commitment to inclusion.
How to Validate PDF/UA Conformance
Manual inspection is not sufficient for PDF/UA. The standard is designed to be machine-testable, and several tools exist for validation:
- PAC (PDF Accessibility Checker) — A free tool from the PDF/UA Foundation that checks documents against PDF/UA requirements and generates detailed reports. It is the most widely used validator in the accessibility community.
- veraPDF — An open-source, industry-supported validator that can check PDF/UA conformance alongside PDF/A and other ISO standards.
- The Matterhorn Protocol — Not a tool itself, but a comprehensive checklist of all possible PDF/UA failure conditions. It defines 31 checkpoints with 136 failure conditions, distinguishing between those that can be checked by software and those requiring human judgment. Learn more in our guide to the Matterhorn Protocol.
PDF/UA-1 vs PDF/UA-2
PDF/UA-1 (ISO 14289-1, published 2012) is based on PDF 1.7 and remains the most widely supported version. Most tools, validators, and workflows target PDF/UA-1 today.
PDF/UA-2 (ISO 14289-2, published 2024) is based on PDF 2.0 and introduces improvements including better support for mathematical content (MathML), enhanced metadata capabilities, and more precise requirements for certain structural elements. Adoption is still in its early stages, and most organizations should focus on PDF/UA-1 conformance for now while keeping PDF/UA-2 on their radar.
Getting Started
Achieving PDF/UA conformance across an entire document library can feel overwhelming, especially for universities managing thousands of legacy PDFs alongside new content. The key is to start with a clear picture of where your documents stand today.
Aelira's PDF accessibility tools can scan your documents against PDF/UA requirements, identify specific failures, and automatically remediate many common issues — from missing structure tags to absent alt text. If you are working toward accessibility compliance and need to bring your PDF library up to standard, it is a practical place to start.
Aelira Team
•Accessibility EngineersThe Aelira team is building AI-powered accessibility tools for higher education. We're on a mission to help universities meet WCAG 2.1 compliance before the DOJ ADA Title II deadline (April 26, 2027 for large public entities).
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