What makes a PDF accessible?
A screen reader can't "see" a page. It reads the PDF's hidden structure, called tags, to know what's a heading, what's a list, what's a table and what order to read things in. An accessible PDF has:
| Element | Why it matters |
|---|---|
| Tags for headings, paragraphs, lists and tables | Screen readers announce structure and let users jump between headings |
| Logical reading order | Columns, sidebars and footnotes are read in the right sequence |
| Alt text on meaningful images | Describes charts, photos and diagrams to people who can't see them |
| Real text, not scanned images | Screen readers can't read pictures of words |
| Document title and language set | Announced when the file opens; correct pronunciation |
| Sufficient colour contrast | Readable for people with low vision or colour blindness |
| Accessible forms with labelled fields | Users know what each field asks for |
| Table header cells marked | Data cells are announced with their column and row |
The legal picture
United States
- Section 508 requires federal agencies' electronic content, including PDFs, to meet WCAG 2.0 Level AA.
- ADA Title II: a 2024 Department of Justice rule requires state and local governments' web content, including documents such as PDFs, to meet WCAG 2.1 Level AA. In April 2026 the DOJ extended the deadlines by one year: to April 26, 2027 for entities serving 50,000 or more people, and April 26, 2028 for smaller entities and special districts.
- Businesses open to the public face ADA Title III claims over inaccessible websites and documents, even without a specific technical rule.
United Kingdom
- The Public Sector Bodies Accessibility Regulations 2018 require public sector websites and documents to meet WCAG 2.2 Level AA, with some exemptions, such as certain older documents.
- The Equality Act 2010 requires service providers to make reasonable adjustments, which can include accessible documents.
The easiest route: build it in the source
Fixing an untagged PDF afterwards is slow and fiddly. Building accessibility into the original document takes minutes:
In Microsoft Word
- Use built-in heading styles (Heading 1, 2, 3), not just bigger bold text.
- Use Word's bullet and numbering buttons for lists.
- Insert real tables, and mark the header row (Table Design → Header Row, plus Repeat as header row).
- Add alt text to images (right-click → View Alt Text). Mark purely decorative images as decorative.
- Use meaningful link text, such as "Download the 2026 report", not "click here".
- Set the document title (File → Info → Properties).
- Run Review → Check Accessibility and fix the issues it reports.
- Export with File → Save As → PDF, and in Options tick Document structure tags for accessibility.
In Google Docs
Use heading styles and alt text the same way, then File → Download → PDF. Google Docs adds basic tags, but check the result, because complex layouts may need fixing in a dedicated PDF editor.
Writing good alt text
- Describe the purpose, not every detail. For a chart: "Bar chart: sales rose from £1.2m in Q1 to £1.6m in Q4."
- Don't start with "Image of"; screen readers already say it's an image.
- If a chart is complex, put the key figures in the text or a table too.
- Mark decorative images (borders, background photos) as decorative so they're skipped.
How to check your PDF
- Automated check: Adobe Acrobat Pro's Accessibility Check, or the free PAC (PDF Accessibility Checker) for PDF/UA.
- Keyboard and screen reader test: open the PDF with NVDA (free, Windows) or VoiceOver (built into Mac and iPhone), and listen. Does it read in the right order? Are headings announced?
- Zoom test: zoom to 200%. Is everything still readable?
Consider HTML instead
For information people read on screen, an HTML web page is usually more accessible than any PDF. It reflows on phones, works with every assistive technology and is easier to keep up to date. Use PDF when people need to print, sign or keep a fixed copy. You can turn a PDF into a clean web page with PDF to HTML as a starting point.
Frequently asked questions
Can I make a scanned PDF accessible?
Only after OCR adds real text, and then it still needs tags and a reading order. Where possible, recreate the document from its source instead.
Do I have to use PDF?
No, and often you shouldn't. UK government guidance generally prefers publishing information as HTML web pages, which are usually more accessible than PDFs.
Is Adobe's accessibility checker enough?
Automated checkers catch missing tags and alt text, but they can't judge whether alt text is meaningful or the reading order makes sense. Test with a screen reader too.
What is PDF/UA?
PDF/UA (ISO 14289) is the international standard for universally accessible PDFs. PDF/UA-1 was published in 2014 and PDF/UA-2, based on PDF 2.0, in 2024.