How to make an accessible PDF
PDFs are where accessibility work often stops: flyers, menus, forms, reports. A PDF can be accessible, but only if it's made that way. A scanned or image-only PDF is a blank page to a screen reader.
First, ask: does this need to be a PDF?
If people read it on a screen, a normal web page is almost always easier for everyone: it reflows on a phone, it's searchable, and it's accessible with far less effort. Keep PDFs for things people actually print or sign, and publish the same content as HTML too.
The four things every PDF needs
- Real text. Text you can select and copy, not a picture of text. Scanned pages need OCR (text recognition), and then a careful check, because OCR makes mistakes.
- Tags. A hidden structure that tells assistive technology what's a heading, a paragraph, a list, a table or an image, and the order to read it in. An untagged PDF is read as one undifferentiated block, if at all.
- A document title. Set in the document properties and shown in the window title, instead of a file name like “FINAL_v3_print.pdf”.
- A language. So a screen reader pronounces the text with the right voice.
On top of that: alt text for meaningful images, images marked as decoration when they're not, table header cells, and links with clear text. The international standard for accessible PDFs is PDF/UA (ISO 14289).
Export it properly from the start
Fixing a finished PDF is slow. Making the source document accessible and exporting it with tags is quick.
- Word and Google Docs: use the built-in heading styles, add alt text to images, and use real lists and tables. In Word, export with “Document structure tags for accessibility” turned on.
- InDesign: set up paragraph styles mapped to export tags, anchor images in the text flow and give them alt text, set the article order, then export as tagged PDF.
- Design tools that only export flattened images: don't use them for anything people need to read. Publish the content as HTML text and offer the designed version as an extra.
Check it
- Try to select a sentence. If you can't, there's no text layer.
- Open the document properties: is there a title, and is it set to show instead of the file name? Is a language set?
- Run the accessibility checker built into Adobe Acrobat, or the free PAC (PDF Accessibility Checker) on Windows.
- Open the tags or reading order view and check that headings, lists and tables are tagged as such, in the right order.
- Listen to a page with a screen reader.
Linking to PDFs
Say it's a PDF in the link text, with its size if it's large: “Catering menu (PDF, 2 MB)”. That tells people a download is coming and lets them decide.
Practical takeaways
- Publish important content as HTML first; treat PDFs as a copy.
- Build accessibility into the source file, and export tagged.
- Never publish a scanned page or a flattened image as the only version.
- Replace old PDFs as you update them, starting with the ones people open most.
What Scanpoof checks, and what needs a person
Found automatically
- Every PDF linked from your pages
- During site scans: whether each linked PDF is tagged, has a title, has a language set and has real text
Needs a person
- Whether the tags and reading order are correct
- Alt text and table structure inside the PDF
- Whether the content should be a web page instead