PDF Accessibility Guide — Make PDFs Everyone Can Use

Updated Feb 20245 min read

Your organization just published its annual report as a PDF. It looks polished — clean layout, charts, branded colors. Then someone using a screen reader tries to open it. The reading order jumps around randomly, images have no descriptions, and headings aren't tagged. For that person, the document is essentially unusable. PDF accessibility is about making sure that never happens.

Accessibility isn't optional anymore. Government agencies, educational institutions, and many businesses are legally required to produce accessible documents. Beyond compliance, it's the right thing to do. Roughly one in five people lives with some form of disability, and many of them rely on assistive technology to consume digital content. A PDF that ignores accessibility shuts out a significant portion of your audience.

Why PDF Accessibility Matters

Accessible PDFs benefit more people than you might expect. Screen reader users are the most obvious group — they rely on properly structured documents to navigate and understand content. But accessibility also helps people with low vision who use magnification software, people with cognitive disabilities who benefit from clear document structure, and even users on mobile devices where a well-structured PDF reflows more predictably.

There's also the legal dimension. In the United States, the ADA and Section 508 require accessible digital documents from government agencies and organizations receiving federal funding. The European Accessibility Act sets similar standards across EU member states. Lawsuits over inaccessible PDFs have increased significantly in recent years, and courts have consistently ruled that digital documents fall under accessibility requirements.

From a practical standpoint, accessible PDFs are simply better documents. Proper tagging improves search engine indexing. Clear reading order makes content easier to follow for everyone. Alt text on images helps when images fail to load. Good accessibility practices overlap with good document design.

Key Elements of an Accessible PDF

Making a PDF accessible involves several structural components. Here are the essentials:

  • Document tags and structure — Tags define the logical structure of a PDF: headings, paragraphs, lists, tables, and figures. Without tags, a screen reader sees a flat stream of text with no hierarchy. Proper tagging tells assistive technology what each element is and how it relates to the rest of the document.

  • Alt text for images — Every meaningful image needs alternative text that describes its content or purpose. Decorative images should be marked as artifacts so screen readers skip them. Charts and graphs need descriptions that convey the data, not just "chart" or "graph."

  • Reading order — The order in which a screen reader encounters content must make logical sense. In a multi-column layout, the reading order should follow the intended flow — not jump between columns randomly. This is often the trickiest part to get right.

  • Language declaration — The document's primary language must be specified in its metadata. This tells screen readers which pronunciation rules and voice to use. If sections contain a different language, those should be tagged separately.

  • Bookmarks and navigation — Longer documents should include bookmarks that map to the heading structure. This gives all users — not just screen reader users — a way to jump between sections quickly.

  • Table structure — Data tables need proper header cells marked as headers and associated with their data cells. Without this, a screen reader reads table content as a meaningless sequence of values.

How to Improve PDF Accessibility

The best time to build accessibility is before the PDF exists — at the source document stage. But many PDFs already exist and need remediation. Here's a practical approach for both scenarios.

Start with OCR for scanned documents. If your PDF is a scan or image-based file, it has zero accessibility. Screen readers can't read image pixels. The first step is running OCR on the PDF to add a searchable text layer. Our OCR tool processes scanned pages and embeds real text that assistive technology can read.

Use proper headings in your source document. Whether you're working in Word, PowerPoint, or Google Docs, use the built-in heading styles (Heading 1, Heading 2, etc.) rather than just making text bold and large. When you export to PDF, those headings carry over as tagged structure. If you need to convert a PDF back to Word for editing, that's a good first step.

Add alt text to every meaningful image. In your source application, right-click images and add alternative text. Be specific — "Bar chart showing Q3 revenue increasing 12% over Q2" is useful. "Chart" is not. For purely decorative images, mark them as decorative so they're skipped.

Set the document language. In Word, this is under document properties. In Acrobat, it's in the document properties dialog. A missing language tag means screen readers have to guess, which often leads to mangled pronunciation.

Check and fix reading order. After exporting to PDF, open it in a tool that shows the tag tree or reading order. Verify that content flows logically. Multi-column layouts, text boxes, and floating elements are common trouble spots.

Add bookmarks for long documents. Any document over a few pages benefits from bookmarks. These typically mirror the heading structure and give readers a clickable table of contents. You can add page numbers as well to help with navigation.

Common Accessibility Issues and Fixes

Here are the problems that come up most often when auditing PDF accessibility:

No tags at all. This is the most common issue. A PDF without tags is nearly impossible for screen readers to interpret correctly. Fix: regenerate the PDF from a properly structured source document, or use a PDF remediation tool to add tags manually.

Images without alt text. Every informative image, chart, logo with text, and diagram needs descriptive alt text. Fix: add alt text in the source document before exporting, or edit the PDF directly to add it.

Incorrect reading order. The visual layout looks fine, but the underlying reading order is scrambled. This happens frequently with multi-column documents, headers, footers, and sidebars. Fix: reorder the tag tree in the PDF, or adjust the source document layout.

Missing document title. The document properties should include a meaningful title, and the PDF should be set to display the title (not the filename) in the title bar. Fix: set the title in document properties.

Untagged form fields. Interactive forms need labels associated with each field. Without labels, screen reader users can't tell which field is which. Fix: add proper form field labels and tooltips.

Color-only information. If you use color alone to convey meaning — like red text for errors — users who can't perceive color miss the message. Fix: add text labels, patterns, or icons alongside color coding.

Tools That Help

Several approaches and tools can improve PDF accessibility:

OCR for scanned documents. The absolute first step for any scanned PDF is running optical character recognition. Without a text layer, nothing else matters — screen readers need text to read. Use our OCR PDF tool to convert image-based pages into searchable, readable text.

Proper conversion from source formats. Starting from a well-structured Word document or PowerPoint presentation gives you a massive head start. Use heading styles, alt text, and table headers in the source, then export to PDF. If you receive a PDF and need to restructure it, converting to Word first often makes remediation easier.

PDF editing tools. For quick fixes — adding missing text, correcting content, or editing a PDF directly — an online editor can handle straightforward changes without needing desktop software.

Accessibility checkers. Adobe Acrobat Pro includes a built-in accessibility checker. Free alternatives like PAC (PDF Accessibility Checker) can identify structural issues. These tools flag missing tags, alt text, reading order problems, and other violations.

Testing PDF Accessibility

Creating an accessible PDF isn't complete until you've tested it. Here's a practical testing approach:

  1. Run an automated checker — Use the accessibility checker in Acrobat or PAC 2024 to catch structural issues. Automated tools find missing tags, alt text gaps, and language settings quickly.

  2. Test with a screen reader — Automated checks can't catch everything. Open the PDF with NVDA (free on Windows), VoiceOver (built into macOS/iOS), or JAWS. Listen to how the document reads. Does the order make sense? Are images described? Can you navigate by headings?

  3. Check keyboard navigation — Tab through the document. Can you reach every link and form field? Is the focus order logical? Interactive elements should be reachable without a mouse.

  4. Verify color contrast — Text should have sufficient contrast against its background. WCAG 2.1 requires a minimum ratio of 4.5:1 for normal text and 3:1 for large text. Use a contrast checker tool to verify.

  5. Review on mobile — Open the PDF on a phone or tablet. Does it reflow reasonably? Can you pinch to zoom? A well-tagged PDF generally performs better on mobile screens.

FAQ

What makes a PDF accessible?

An accessible PDF has proper document tags (headings, paragraphs, lists), alternative text for images, a logical reading order, declared language, and bookmarks for navigation. These elements allow screen readers and other assistive technology to interpret and present the content correctly.

Are scanned PDFs accessible?

Not by default. A scanned PDF is essentially a collection of images — screen readers can't read image pixels. You need to run OCR first to add a text layer, then add proper tags and structure on top of that.

What accessibility standards apply to PDFs?

The main standards are WCAG 2.1 (Web Content Accessibility Guidelines), PDF/UA (Universal Accessibility — ISO 14289), Section 508 (U.S. federal requirement), and the European Accessibility Act. PDF/UA is the most specific to PDF documents and defines detailed technical requirements.

How do I check if my PDF is accessible?

Use an automated tool like Adobe Acrobat's built-in accessibility checker or the free PAC (PDF Accessibility Checker). Then test manually with a screen reader like NVDA or VoiceOver. Automated tools catch structural issues; manual testing catches reading order and context problems.

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