Accessible PDFs are essential for reaching all readers, including people who use screen readers, have low vision, or rely on keyboard navigation. Whether you're a business publishing reports or a student submitting assignments, accessible PDFs reflect inclusive design.
What Makes a PDF Inaccessible?
Many PDFs are created from scanned images or exported without proper tags, making them:
- Unreadable by screen readers, the content is a flat image, not selectable text
- Poorly structured, no headings or reading order defined
- Color-contrast issues, light text on light backgrounds
- Missing alt text, images have no descriptions for visually impaired readers
Key Accessibility Features in PDFs
Tagged Structure
PDF tags define the document's logical structure: headings, paragraphs, lists, tables. Screen readers rely on these tags to navigate the content. When exporting from Word or Google Docs, most tools preserve heading structure automatically.
Alt Text for Images
Every image in a PDF should have a text description. This is added in the source document (Word, InDesign) before exporting to PDF, or via advanced PDF editors.
Readable Fonts and Contrast
- Use fonts of at least 12pt for body text
- Ensure sufficient contrast between text and background (4.5:1 ratio minimum)
- Avoid using color alone to convey meaning
Searchable Text
Scanned PDFs are images, they contain no selectable text. Converting them to searchable text (OCR) is essential for accessibility. See how to make a PDF searchable for tools and steps.
Logical Reading Order
Screen readers read PDFs in the order content is tagged, which may not match visual layout. Multi-column documents and complex layouts often need manual reordering.
Quick Wins for Accessibility
If you're creating PDFs from scratch:
- Use proper heading styles (H1, H2, H3) in your source document
- Add alt text to all images before exporting
- Choose high-contrast color combinations
- Export to PDF using "Accessible PDF" settings in Word or Adobe InDesign
- Run a quick screen reader test after export
Editing Existing PDFs for Accessibility
For adding missing text, annotations, or stamps to an existing PDF, Docento.app provides a fast, browser-based editor that keeps your files private. Learn more about what you can do in the beginners guide to editing PDFs.
