Accessibility ≠ Overlay · 22
Accessibility ≠ Overlay: when downloadable documents exclude people too
📅 October 2026 ⏱ 7 min read
A PDF can look perfect on screen and still be unusable with a screen reader. Website accessibility includes the documents visitors are expected to download.
PDFs are part of the user journey
Reports, invoices, manuals, menus, forms and terms are often published as PDFs. An accessible website still excludes people if its essential documents cannot be read.
A visual file is not necessarily accessible
A scanned PDF may contain only page images. Without readable text, tags or structure, assistive technology may struggle. OCR can recover text but does not guarantee correct document structure.
Headings and reading order
Headings need semantic structure, not just larger or bold text. Reading order should follow the intended sequence, especially in multi-column layouts.
Images, charts and tables
Informative images need appropriate text alternatives. Complex charts may require fuller explanations. Tables need correctly identified headers and meaningful row-column relationships.
Links and PDF forms
A link labelled ‘click here’ does not explain its destination. PDF form fields need understandable labels and instructions and must work with a keyboard.
Language, metadata and navigation
Set the document language and a useful title. Add bookmarks where appropriate, and check contrast, zoom and text selection.
How to test before publishing
Start with a well-structured source document and export tagged PDF. Check reading order, images, tables, keyboard navigation and screen-reader output. Automated checks alone are not sufficient.
What Blind Reader can do
Blind Reader includes a PDF.js-based document reader and supporting features. It can help users access content, but cannot reliably recreate all missing document semantics or replace accessible PDF authoring.
Offer an accessible alternative
Where possible, publish the content as accessible HTML too. Treat any PDF as part of your digital service and test it before release.