Improve PDF readability: accessibility tips

2 min read·25 July 2026

A well-readable PDF is accessible to everyone — including people with visual impairments. Learn the basics of accessible PDFs.

Why accessibility in PDF matters

People with visual impairments use screen readers that read text from a PDF aloud. A PDF saved as an image (scanned) cannot be read aloud — the person receives no information. By law, government organizations in the EU are required to make digital documents accessible (WCAG 2.1).

Make text selectable: OCR

If your PDF is a scan, use the OCR tool on PDFrust to make the text recognizable. After OCR the text is selectable, copyable and readable by screen readers. This is the first and most impactful step toward an accessible PDF.

PDF OCR — scan to text

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High contrast and readable text

Text in a PDF must have sufficient contrast with the background. Black text on white background (ratio 21:1) is optimal. Gray text on white background (e.g. light gray body text) is difficult to read for people with low contrast vision. Also avoid color text like red on green background — also bad for colorblind users.

Font size and white space

Minimum readable font size for PDF documents: 10 pt for footers, 12 pt for body text. Smaller text is hard to read for people with reduced vision. Use the Margins tool to preserve sufficient white space around text — this improves readability for everyone.

Document structure and navigation

An accessible PDF has a logical structure: titles as H1, sections as H2, subsections as H3. This can only be set in the source (in Word or InDesign). A PDF file itself can be given document tags afterwards with Adobe Acrobat Pro (Accessibility → Add Tags to Document). This helps screen readers understand the structure.