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What is PDF/UA and Why It Matters for Accessibility

Accessibility is a legal and ethical requirement. Learn about the PDF/UA standard and how to create documents that are accessible to everyone.

Universal Access symbol integrated with a PDF document icon

What is PDF/UA and Why It Matters for Accessibility

The internet is for everyone. This includes people with visual impairments who use screen readers (like JAWS or NVDA) to navigate the digital world.

While web accessibility (WCAG) gets a lot of attention, document accessibility is often overlooked. A standard PDF is often a “black box” to a screen reader—it might read the text, but it won’t understand the order, the headings, or the images.

PDF/UA (Universal Accessibility) is the ISO standard (ISO 14289) that defines how to create PDFs that are truly accessible.

1. The “Tag Tree”

The core of PDF/UA is the Tag Tree. This is a hidden layer of structure behind the visual content. It tells the screen reader:

  • “This text is a Heading Level 1 (H1).”
  • “This is a List with 3 items.”
  • “This is a Data Table, and these are the headers.”

Without tags, a screen reader might read a multi-column article straight across the page (reading column 1 line 1, then column 2 line 1), resulting in gibberish. Tags define the logical reading order.

2. Alt Text for Images

PDF/UA requires that all meaningful images have Alternative Text (Alt Text). This is a text description that the screen reader reads aloud.

  • Bad: “image123.jpg”
  • Good: “Bar chart showing Q3 revenue growth of 15%.”

Decorative images (like background swooshes) must be tagged as “Artifacts” so the screen reader ignores them completely.

3. Font Embedding and Unicode

For a computer to “read” text, it needs to know what characters the glyphs represent. PDF/UA mandates that all fonts map correctly to Unicode. This ensures that the letter “A” is actually recognized as the character “A” and not just a drawing of a triangle.

  • Legal Compliance: In many jurisdictions, including the US (Section 508, ADA) and the EU (European Accessibility Act), providing accessible documents is a legal requirement for government agencies and many private businesses.
  • Market Reach: Over 1 billion people worldwide have some form of disability. Inaccessible documents exclude a massive segment of the population.
  • SEO: The same structure that helps screen readers (headings, alt text) also helps search engines understand and index your PDF content.

5. How to Achieve PDF/UA Compliance

Creating PDF/UA compliant documents manually is difficult. It involves using tools like Adobe Acrobat Pro to manually tag every element.

For automated workflows, you need a generator that supports Tagged PDF output.

  • Semantic HTML: If generating from HTML, use proper tags (<h1>, <table>, <ul>). A good converter will map these HTML tags to PDF tags automatically.
  • Validation: Use tools like the PAC (PDF Accessibility Checker) to verify your documents against the standard.

Conclusion

Accessibility is not a “nice to have”; it is a fundamental quality of a professional document. Adopting PDF/UA ensures that your information is available to everyone, regardless of how they access it.

Generate accessible documents automatically. MergeCanvas is designed to produce tagged, PDF/UA compliant files from your data, ensuring you meet compliance standards effortlessly.