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PDF Accessibility — Making PDFs Work With Screen Readers

·10 min read

About 2.2 billion people worldwide have some form of vision impairment. That's not a small number. And yet, most PDFs are basically unusable for anyone relying on a screen reader. The text is there, but the structure is missing.

I'll admit this isn't the most exciting topic. But it matters. And making your PDFs accessible is easier than you probably think. Let me show you how.

What Makes a PDF "Accessible"?

An accessible PDF has structure that machines can read, not just text that humans can see. Think of it like the difference between a printed book and an audiobook. The printed book has visual cues — headings are bigger, paragraphs have spacing, images break up the text. A screen reader can't see any of that. It needs to be told "this is a heading" and "this image shows a chart comparing sales figures."

Specifically, an accessible PDF has:

  • Tagged structure: Headings, paragraphs, lists, and tables are labeled with tags
  • Reading order: The content flows logically when read top to bottom
  • Alt text: Images have descriptions for screen readers
  • Bookmarks: For long documents, bookmarks let users jump between sections
  • Document language: The language is specified so the screen reader uses the correct pronunciation

Why Should You Care?

Beyond basic human decency (making your content available to everyone), there are practical reasons:

Legal requirements are growing. In many countries, government documents and business communications must be accessible. The Americans with Disabilities Act, European Accessibility Act, and similar laws are being enforced more aggressively.

Search engines also benefit from well-structured PDFs. Tagged PDFs are easier for Google to index and understand. So accessibility improvements can actually help your SEO. Win-win.

How to Check If Your PDF Is Accessible

Open your PDF in Adobe Acrobat Reader (the free version). Go to Edit → Accessibility → Quick Check. It'll tell you the basics — whether tags exist, if the reading order makes sense, and whether the document language is set.

For a more thorough check, the free PAC (PDF Accessibility Checker) tool from the PDF/UA Foundation is the gold standard. It tests against the PDF/UA accessibility standard and gives you a detailed report of what passes and what needs fixing.

Creating Accessible PDFs from Word

The easiest way to create an accessible PDF is to start from a well-structured Word document. That means actually using heading styles (Heading 1, Heading 2) instead of just making text bold and bigger. It means using real lists instead of manually typing bullet points. It means adding alt text to images.

Here's the step-by-step:

  1. Use built-in heading styles for all headings (don't just format text to look like a heading)
  2. Right-click images → Edit Alt Text → Write a meaningful description
  3. Use real tables with header rows marked (Table Design → Header Row checkbox)
  4. Run the Accessibility Checker (Review → Check Accessibility)
  5. Fix any issues the checker finds
  6. Export to PDF using File → Save As → PDF (not Print to PDF — this loses tags)

That last point is important. "Print to PDF" creates a flat image-like PDF. "Save As PDF" preserves the structure and tags. It's the same-looking output but wildly different for screen readers.

Fixing Existing PDFs

If you have a PDF that's not accessible, fixing it ranges from easy to painful depending on how it was created.

If the source document exists (Word, Google Docs, etc.), fix the source and re-export. That's always easier than editing the PDF directly.

If you only have the PDF, Adobe Acrobat Pro has tools for adding tags and structure. It's not free, but it's the most reliable option. Go to Tools → Accessibility → Add Tags to Document. Then review and correct the auto-generated tags.

For free options, LibreOffice can import PDFs and add some structure, though the results vary depending on the PDF's complexity. You can also use the axesPDF QuickFix tool for basic remediation.

Writing Good Alt Text

Alt text is the description a screen reader announces when it encounters an image. Writing good alt text is a skill, and most people get it wrong at first.

Rules of thumb:

  • Be specific: "Bar chart showing Q3 revenue of $2.4M, up 15% from Q2" beats "chart"
  • Be concise: 1-2 sentences. Don't write a paragraph.
  • Skip "image of" or "picture of": Screen readers already announce it's an image
  • Decorative images get empty alt text: If an image is purely decorative (a border, a divider), mark it as decorative or leave alt text empty so screen readers skip it

Common Mistakes

Using scanned PDFs without OCR: A scanned document is just a picture. Screen readers can't read pictures of text. Always run OCR on scanned documents. We have a guide on making scanned PDFs searchable that covers this.

Color as the only indicator: Don't use color alone to convey meaning. "The items in red are overdue" means nothing to someone who can't see color. Add text labels or symbols too.

Complex tables without headers: Tables need header rows and columns marked so screen readers can announce "Row 3, Column B: $450" instead of just "450."

Missing document title: Set the document title in File → Properties. Screen readers announce this when opening the file. "Untitled" or "doc_final_v3.pdf" isn't helpful.

Start Small

You don't have to make every PDF perfectly accessible overnight. Start with these three things and you'll cover 80% of accessibility needs:

  1. Use real heading styles in your source document
  2. Add alt text to meaningful images
  3. Use "Save As PDF" instead of "Print to PDF"

Those three steps take almost no extra time and make a massive difference for anyone using assistive technology. Accessibility isn't about perfection — it's about making things better, one document at a time.