PDFs are part of your website
A PDF you publish on your site is web content, and WCAG applies to it. EN 301 549 also has a dedicated clause for documents. A PDF made of images, or exported without structure, is hard or impossible to use with a screen reader.
What an accessible PDF needs
- Tags that mark up headings, paragraphs, lists and tables (1.3.1 Info and Relationships). Tables need header cells.
- A logical reading order, even with columns and boxes (1.3.2 Meaningful Sequence).
- Alt text for informative images; decorative ones marked as artifacts (1.1.1 Non-text Content).
- Language set for the document and for passages in other languages (3.1.1 Language of Page, 3.1.2 Language of Parts).
- A meaningful title, shown in the window instead of the file name (2.4.2 Page Titled).
- Bookmarks to help people find their way in longer documents.
- Contrast of at least 4.5:1 for body text (1.4.3 Contrast (Minimum)); try our contrast checker.
- Form fields that are labelled and reachable by keyboard.
PDF/UA: the standard for accessible PDF
PDF/UA (Universal Accessibility) is standardised as ISO 14289. Part 1, ISO 14289-1:2014 (PDF/UA-1), sets out how a PDF must be built so that assistive technology can read it reliably. WCAG describes what people need; PDF/UA describes how the file format delivers it. The two work together.
Get it right at the source: Word and InDesign
The easiest accessible PDF starts with an accessible source file. Fixing a finished PDF is slow and has to be repeated after every edit.
- Use styles: Heading 1, 2, 3 for headings, real lists, no empty lines for spacing.
- Add alt text to images in the source document.
- Set title and language in the document properties.
- Keep tables simple and mark the header row.
- Export properly: use Save as PDF or Export with tagging or accessibility options switched on. Do not use “Print to PDF”; it throws the structure away.
- InDesign: map paragraph styles to tags, set the order in the Articles panel and export a tagged PDF.
Checking with PAC and by hand
The free PDF Accessibility Checker (PAC) tests files against PDF/UA and WCAG. It shows at a glance whether a title, a language and a tag structure are present.
As the Swiss foundation “Zugang für alle” (Access for all) points out, PAC does not replace manual checking. Whether alt text fits, a heading makes sense or the reading order holds up is a human judgement, ideally made with a screen reader.
Does it need to be a PDF?
Often a normal web page is the better choice. It reflows on any screen, zooms cleanly and is usually easier to keep accessible. PDF earns its place for documents that will be printed or archived unchanged.
Frequently asked questions
Can I just upload a scanned document?
No. A scan is an image with no text or structure. Even with text recognition, tags, reading order and alt text are usually missing.
Do you test PDFs in an audit?
PDFs that are part of the agreed scope are tested. Name them when you request the audit.
How do PDF/UA and WCAG differ?
WCAG says what must be accessible to people. PDF/UA says how the PDF file must be structured. A good PDF meets both.
Sources
How does your website do?
The free check tests your home page in two minutes. The audit decides all 55 criteria, by a person.