Around 15% of the world's population lives with some form of disability. When you publish a PDF that isn't accessible, you're locking out a significant number of potential readers — and in many places, breaking the law.
A PDF that looks perfectly fine on screen can be completely unusable for someone relying on a screen reader (software that reads content aloud or outputs it to a Braille display). Without proper structure, a screen reader might read a two-column layout as jumbled nonsense, skip images entirely, or present a table as an incomprehensible stream of numbers.
Beyond individual access, there are legal requirements. The EU European Accessibility Act (effective June 2025), the US ADA and Section 508, the UK Public Sector Bodies Accessibility Regulations, and similar laws in Canada, Australia, and elsewhere increasingly require that published documents — including PDFs — meet accessibility standards, typically WCAG 2.1 AA and the PDF-specific PDF/UA (ISO 14289) standard.
Tags are the single most important accessibility feature. A tagged PDF contains a hidden structure tree that labels each piece of content: headings (<H1> through <H6>), paragraphs (<P>), lists (<L>, <LI>), tables (<Table>, <TR>, <TD>, <TH>), figures (<Figure>), and more.
This structure lets a screen reader navigate the document meaningfully — jumping between headings, reading table headers with each cell, and distinguishing a footnote from body text. Without tags, the screen reader can only guess at the structure based on visual position, which fails for anything beyond the simplest single-column text.
The visual layout of a PDF doesn't determine the order in which content is read. A two-column page, a sidebar, a pull quote — these all need an explicit reading order so assistive technology presents them in a sequence that makes sense. The tag tree defines this order. If it's wrong, a screen reader might read a page footer before the second paragraph, or interleave columns unpredictably.
Every meaningful image needs alt text — a concise description of what the image conveys. Decorative images (borders, spacers, backgrounds) should be marked as artefacts so screen readers skip them entirely. Charts and diagrams need descriptions that communicate the data or relationship, not just "chart" or "figure 3".
The PDF's metadata should declare its primary language (e.g. English, Greek, German). This tells the screen reader which pronunciation rules to use. Documents with passages in multiple languages should tag each passage with the correct language so the voice switches appropriately.
Tables need proper header cells (<TH>) marked distinctly from data cells (<TD>), and for complex tables, header-cell associations so a screen reader can announce "Column: Revenue, Row: Q3" rather than just a bare number. Avoid using tables for visual layout — layout tables confuse screen readers that expect tabular data.
For longer documents, bookmarks (the clickable outline panel in a PDF viewer) give all readers — not just those using assistive technology — a way to navigate quickly. They're generated automatically from headings in most authoring tools.
Information conveyed through colour alone is invisible to people with colour vision deficiency. Use labels, patterns, or other visual cues alongside colour. Text should meet a minimum contrast ratio of 4.5:1 against its background (3:1 for large text) per WCAG guidelines.
The easiest path to an accessible PDF is to start right in the source document:
If you have a PDF without tags or with broken structure:
A tagged PDF contains a hidden structure tree that labels each piece of content — headings, paragraphs, images, tables, lists — so assistive technology can present the document in a meaningful order rather than just reading raw text left-to-right, top-to-bottom.
Partially. OCR converts the image to searchable text, which is essential, but you'll still need to add tags, reading order, and alt text manually. Starting from a born-digital source is far easier.
In many jurisdictions, yes — for public-sector documents and often for private organisations too. The EU's European Accessibility Act, the US ADA and Section 508, and the UK's Public Sector Bodies Accessibility Regulations all set requirements that effectively mandate accessible PDFs.
Last updated: 3 September 2026.