What Is PDF Accessibility?

PDF accessibility refers to the practice of creating PDF documents that can be effectively used by people with disabilities, including those who are blind or have low vision, deaf or hard of hearing, have motor impairments, or have cognitive disabilities.

An accessible PDF isn't just a PDF that "can be opened" — it's a document that conveys its information to all users, regardless of how they interact with it. For a sighted user reading on a screen, a document's meaning comes from visual layout — headings are larger and bolder, tables have visible grid lines, images illustrate concepts. For a user relying on a screen reader, that visual information must be translated into a structured, navigable format that can be read aloud in a logical order.

Why PDF Accessibility Matters

Legal Requirements

In many jurisdictions, digital accessibility is a legal obligation:

United States:

• Americans with Disabilities Act (ADA): Requires that places of "public accommodation" — increasingly interpreted to include websites and digital content — be accessible
• Section 508 of the Rehabilitation Act: Requires federal agencies and organizations receiving federal funding to make electronic content accessible
• CVAA (21st Century Communications and Video Accessibility Act): Extends accessibility requirements to modern communications

European Union:

• European Accessibility Act (EAA): Requires products and services, including digital documents, to meet accessibility standards by 2025
• Web Accessibility Directive: Requires public sector websites and mobile applications to meet WCAG 2.1 AA standards

Other Jurisdictions:

• Canada: Accessible Canada Act
• UK: Equality Act 2010
• Australia: Disability Discrimination Act 1992

Practical Business Benefits

Beyond legal compliance, accessible documents offer tangible benefits:

• Wider audience reach: Approximately 15% of the world's population has some form of disability
• Better SEO: Search engines can better index well-structured, accessible documents
• Improved usability: Accessibility improvements often enhance the experience for all users
• Brand reputation: Demonstrating commitment to inclusivity strengthens brand perception

What Makes a PDF Accessible?

1. Document Structure (Tags)

The most fundamental requirement for an accessible PDF is proper structural tagging. Tags define the document's logical structure:

• ,

  ,

  : Heading hierarchy for navigation

• : Paragraphs of body text

• , ,

  ,

  : Table structure with headers , : Lists and list items : Images and graphics with alt text : Hyperlinks with descriptive text : Inline elements for language changes or styling Without tags, a screen reader encounters a PDF as a flat stream of text with no indication of headings, paragraphs, or reading order. 2. Reading Order The logical reading order must match the visual layout. For a simple single-column document, this is straightforward. For multi-column layouts, sidebars, and callout boxes, the reading order must explicitly define which content comes first. A screen reader follows the tag order, not the visual position. If tags are ordered incorrectly, a user might hear a sidebar's content inserted in the middle of a paragraph, making the document incomprehensible. 3. Alternative Text for Images Every informative image must have descriptive alternative text (alt text) that conveys the image's purpose: Good alt text: "Bar chart showing quarterly revenue growth: Q1 $1.2M, Q2 $1.5M, Q3 $1.8M, Q4 $2.1M" Bad alt text: "Chart" or "image1.png" Decorative images: Should be marked as artifacts (not tagged) so screen readers skip them 4. Color and Contrast Content must not rely on color alone to convey meaning. For example, if important text is highlighted in red, there should be an additional indicator (bold, asterisk, icon) for users who cannot perceive color. Text must have sufficient contrast against its background: Normal text: Minimum contrast ratio of 4.5:1 Large text (18pt or 14pt bold): Minimum contrast ratio of 3:1 5. Language Specification The document's primary language must be set in the metadata so screen readers use the correct pronunciation rules. If the document contains passages in other languages, those passages should be tagged with the appropriate language attribute. 6. Navigational Aids Accessible PDFs should include: Bookmarks: For documents longer than a few pages Table of contents: With working hyperlinks to each section Page labels: Meaningful page numbers (especially important when PDF page numbers don't match the document's printed page numbers) 7. Form Accessibility If the PDF contains forms: Every form field must have a descriptive label Required fields must be clearly indicated Tab order must follow a logical sequence Error messages must be programmatically associated with their fields How to Create Accessible PDFs From Microsoft Word Use built-in heading styles (Heading 1, 2, 3) instead of manually formatting text Add alt text to all images (right-click → Edit Alt Text) Use the built-in table tool and designate header rows Run the Accessibility Checker (Review → Check Accessibility) before exporting Export to PDF with "Document structure tags for accessibility" enabled From Google Docs Use heading styles from the toolbar Add alt text to images (right-click → Alt Text) Use simple tables with header rows Export as PDF (File → Download → PDF Document) From Adobe InDesign Use paragraph styles mapped to PDF tags Set the Articles panel to define reading order Add alt text to placed images Export with "Create Tagged PDF" enabled Testing PDF Accessibility Automated Testing Tools Adobe Acrobat Pro: Built-in Accessibility Checker (Edit → Accessibility → Full Check) PAC (PDF Accessibility Checker): Free, comprehensive testing tool by the Swiss foundation "Access for all" axe DevTools: Browser extension that can assess PDF accessibility Manual Testing Automated tools catch structural issues but miss many content problems. Manual testing should include: Screen reader testing: Open the PDF with NVDA (free, Windows), JAWS, or VoiceOver (macOS) and listen to how the content is read Keyboard navigation: Can you navigate through the document using only Tab, arrows, and Enter? Zoom testing: Does the document remain usable when zoomed to 200%? Reading order verification: Is content read in a logical sequence? The Role of OCR in Accessibility Scanned PDFs (image-based PDFs) are inherently inaccessible because they contain no text data for screen readers to read. OCR (Optical Character Recognition) is essential for making scanned documents accessible: Run OCR on the scanned PDF to add a text layer (use BloomPDF's OCR PDF tool) The text layer makes the content readable by screen readers For full accessibility, the OCR output should be reviewed and structural tags added Conclusion PDF accessibility isn't optional — it's a legal requirement in many jurisdictions and a moral imperative in all contexts. By following the principles outlined in this guide — proper structure, alt text, color contrast, reading order, and thorough testing — you can create documents that serve all users equally. Tools like BloomPDF's OCR engine help bridge the gap for scanned documents, ensuring that even legacy paper documents can be made accessible in the digital world. Tags accessibilityWCAGADAscreen readersinclusive designtagged pdf Try These Related Tools OCR PDF Make scanned PDFs searchable and selectable PDF to Word Convert PDF files to editable Word documents Merge PDF Combine multiple PDF files into a single document Related Articles Standards & Compliance The Complete Guide to PDF/A: What It Is & Why You Need It Everything you need to know about the PDF/A archival standard — what it is, the different conformance levels, who requires it, and how to create PDF/A documents. Back to All Articles