Making PDFs Accessible: A Complete Guide

Accessible PDFs ensure that everyone, including people with disabilities, can read and understand your documents. Learn how to create PDFs that work for everyone.

What is PDF Accessibility?

An accessible PDF is one that can be read and navigated by people using assistive technologies like screen readers, and by people with visual, motor, or cognitive disabilities.

Why Accessibility Matters

• Legal compliance: Many countries require accessible documents (ADA, Section 508, AODA)
• Larger audience: 15% of the world's population has some form of disability
• Better for everyone: Accessible documents are often better organized and easier to use
• SEO benefits: Searchable, well-structured content performs better

Key Elements of Accessible PDFs

1. Document Structure (Tags)

Tags define the structure of your document - headings, paragraphs, lists, tables. Screen readers use tags to navigate and read content in the correct order.

• Use proper heading hierarchy (H1, H2, H3)
• Mark paragraphs, lists, and tables appropriately
• Define reading order for complex layouts

2. Alternative Text for Images

Every image should have alt text describing its content or purpose. Decorative images can be marked as "artifacts" to be ignored by screen readers.

3. Document Language

Set the document language so screen readers pronounce words correctly. For multilingual documents, mark language changes within the content.

4. Bookmarks and Navigation

Include bookmarks for easy navigation through long documents. These appear in the PDF reader's sidebar and help users jump to sections.

5. Logical Reading Order

In multi-column layouts, content should be tagged in the order it should be read, not the order it appears visually.

6. Accessible Tables

Tables need proper structure:

• Define header cells vs data cells
• Add row and column scope attributes
• Provide table summaries for complex tables

7. Color Contrast

Ensure sufficient contrast between text and background. WCAG recommends 4.5:1 ratio for normal text, 3:1 for large text.

8. Don't Rely on Color Alone

Don't use color as the only way to convey information. Add text labels, patterns, or symbols as alternatives.

Creating Accessible PDFs

From Microsoft Word

1. Use Word's built-in styles (Heading 1, 2, 3, etc.)
2. Add alt text to images (Right-click → Edit Alt Text)
3. Run the Accessibility Checker (Review → Check Accessibility)
4. Export to PDF with "Document structure tags" enabled

From Adobe InDesign

1. Use paragraph styles mapped to tags
2. Set reading order in Articles panel
3. Add alt text to images
4. Export with accessibility options enabled

From Google Docs

1. Use heading styles from the Format menu
2. Add alt text to images (Right-click → Alt text)
3. Download as PDF (File → Download → PDF)
4. Note: May need additional remediation

Fixing Existing PDFs

For PDFs that weren't created accessibly:

1. Use Adobe Acrobat Pro's accessibility tools
2. Add tags using the Tags panel
3. Set reading order
4. Add alt text to images
5. Run the Accessibility Checker

For scanned documents, first run OCR to make text selectable, then add tags.

Testing PDF Accessibility

Automated Testing

• Adobe Acrobat Pro: Tools → Accessibility → Full Check
• PAC (PDF Accessibility Checker): Free, detailed testing
• Online validators: Quick checks for common issues

Manual Testing

• Tab through interactive elements
• Test with actual screen readers (NVDA, JAWS, VoiceOver)
• Check reading order in Tags panel
• Verify all images have appropriate alt text

Common Accessibility Issues

PDF/UA Standard

PDF/UA (Universal Accessibility) is the ISO standard for accessible PDFs. It requires:

• Complete tagging of all content
• Proper document structure
• Alt text for all meaningful images
• Defined document language
• Navigable bookmarks
• Accessible tables and lists

Quick Accessibility Checklist

• ☐ Document is tagged
• ☐ Reading order is logical
• ☐ All images have alt text
• ☐ Document language is set
• ☐ Headings follow proper hierarchy
• ☐ Tables have headers defined
• ☐ Links are descriptive
• ☐ Color contrast is sufficient
• ☐ Bookmarks exist for navigation
• ☐ Title is set in document properties