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.