Making accessible PDFs: a practical checklist

Nearly a quarter of people in the UK report having a disability, and many use assistive technology such as screen readers, magnifiers or voice control. A PDF that looks perfect on screen can be unusable for these readers if it was made without accessibility in mind. The good news is that most of the work happens when the document is created, and a short checklist catches the common problems.

How a screen reader reads a PDF

A screen reader can’t see the page. It relies on tags: a hidden structure, similar to HTML, that labels each part of the document as a heading, paragraph, list, table or image, and puts them in reading order. A PDF with tags is called a tagged PDF. Without tags, a screen reader has to guess the order from the position of characters, which goes badly wrong with columns, tables and sidebars.

The biggest problem: scanned documents

A scanned page is a photograph. To a screen reader it’s a single image with no text at all, so it’s either silent or announces “image”. Scans need optical character recognition (OCR) to turn the picture back into text, and then tagging. If you have the original digital document, export a fresh PDF from that instead of scanning a printout.

A practical checklist

1. Start from an accessible source. In Word, Google Docs or similar, use the built-in heading styles (Heading 1, Heading 2) rather than just making text bold and large.
2. Add alternative text to images. Describe what the image conveys, not what it looks like. A chart’s alt text should state its key finding. Mark purely decorative images as decorative.
3. Use real lists and simple tables. Avoid merged cells and tables used only for layout. Mark the header row.
4. Set the document title and language. The title appears in the reader’s window bar; the language tells screen readers which pronunciation to use.
5. Write meaningful link text. “Download the 2026 fee schedule” rather than “click here”.
6. Check colour contrast. Body text should have a contrast ratio of at least 4.5:1 with its background. Don’t use colour alone to convey meaning, such as red for “overdue”.
7. Export as tagged PDF. In most office software this is an option in the PDF export settings, often on by default. Check it hasn’t been turned off.
8. Test it. Use the accessibility checker in your PDF software, then try reading the document with a screen reader such as NVDA (free, Windows) or VoiceOver (built into Mac and iPhone).

What editing tools do to accessibility

Tags live alongside the pages, in a document-wide structure. Tools that build a new PDF by copying pages, including merging, splitting, extracting and reordering, generally don’t carry that structure across, so the result may lose its tags. That’s true of PDF365’s browser-based tools today.

For documents where accessibility matters, the most reliable approach is to make content changes in the original source file and export a new tagged PDF. Use page tools for drafts and internal documents, and check the final published version with an accessibility checker.

The legal side in the UK

Public sector bodies in the UK must meet accessibility regulations for their websites and the documents on them, using the Web Content Accessibility Guidelines (WCAG) at level AA. Private organisations have duties under the Equality Act 2010 to make reasonable adjustments for disabled people, which can include providing documents in accessible formats. If you publish documents for the public, accessible PDFs, or better still an HTML version of the same content, are the safest path.

Sometimes a PDF isn’t the right format

Government guidance in the UK encourages publishing content as web pages rather than PDFs where possible, because HTML adapts to screen size, zoom and assistive technology far better than fixed pages. PDFs remain the right choice for forms that must be printed, legal documents with fixed wording and material that needs to keep an exact layout. If you’re creating simple documents from scratch, writing them in HTML and converting with HTML to PDF gives you a version for the web and a PDF from the same source.