An accessible PDF can be read by screen readers, navigated with a keyboard, and understood by people with visual, motor, or cognitive disabilities. Accessibility is not just a best practice — it is a legal requirement in many contexts under laws like the ADA, Section 508, and the European Accessibility Act. Starting June 2025, many digital products and services in the EU must meet the requirements of EN 301 549, which includes PDF documents that are publicly distributed or used in commercial transactions. This guide explains what makes a PDF accessible and how to achieve compliance.
Accessible PDFs require proper tag structure, which defines headings, paragraphs, lists, and tables in a logical reading order. Every image needs alternative text describing its content. Tables must have defined header rows and columns. The document language must be specified in the metadata. Links should have descriptive text rather than raw URLs. Color must not be the only way to convey information, and sufficient color contrast is required. Form fields need labels, and the tab order must follow the visual layout logically.
How to Check and Fix PDF Accessibility
1
Run an accessibility check
Use a PDF accessibility checker to scan your document. This identifies missing tags, alt text, reading order issues, and other compliance problems.
2
Add document structure tags
Tag all content elements — headings, paragraphs, lists, tables, and figures. This creates the logical structure that screen readers use to navigate the document.
3
Add alternative text to images
Write descriptive alt text for every meaningful image. Decorative images should be marked as artifacts so screen readers skip them.
4
Set reading order and language
Verify that the reading order matches the visual layout. Set the document language in properties so screen readers use the correct pronunciation.
Accessibility Best Practices
Start with an accessible source document — creating accessible PDFs from well-structured Word or HTML files is much easier than fixing them after export.
Use real text instead of images of text wherever possible.
Test your PDF with an actual screen reader like NVDA or JAWS to catch issues automated tools miss.
Ensure a minimum color contrast ratio of 4.5:1 for normal text and 3:1 for large text.
PDF/UA: The Accessibility Standard for PDFs
PDF/UA (ISO 14289) is the international standard for accessible PDF documents. It defines precise technical requirements: all content must be tagged, the tag structure must correctly reflect the semantic meaning, and the reading order must be logical. Images require alternative text, tables must define header cells, and the document language must be specified. PDF/UA goes beyond general accessibility guidelines by prescribing specific technical criteria for PDF files. Documents that conform to PDF/UA are automatically compliant with the accessibility requirements of EN 301 549 and WCAG 2.1 as well.
Automated and Manual Accessibility Testing
PDF accessibility testing operates on two levels. Automated tools like PAC (PDF Accessibility Checker) verify technical criteria: are all elements tagged, do images have alternative text, is the document language set? These checks cover approximately 30 percent of potential issues. The remaining 70 percent require manual review: is the alternative text meaningful, is the reading order logical, are tables tagged in a comprehensible way? Additionally, test your PDF with a screen reader such as NVDA or JAWS to evaluate the actual user experience. Only the combination of automated and manual testing ensures genuine accessibility.
Creating Accessible PDFs from Source Documents
The most efficient path to accessible PDFs runs through well-structured source documents. In Microsoft Word, use the built-in heading styles, add alternative text to images, and use real lists instead of manually typed bullet points. Tables should be created with defined header rows. When exporting to PDF, select the option for tagged PDF output. InDesign offers similar capabilities with export tags and the ability to define reading order in the Articles panel. HTML-based documents transfer their semantic structure automatically during PDF export. This source-document approach saves considerable time compared to retroactively tagging a finished PDF.