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Guide

PDF accessibility checklist for WCAG 2.1 AA and PDF/UA

Use this to check one document by hand. It covers what automatic checkers cannot decide.

Last reviewed October 20, 2026. General information for public agencies, not legal advice. Rules change, so check the sources below and ask your lawyer or civil rights office what applies to you.

How to use this

Go through the list for one document at a time. You can print this page. WCAG 2.1 AA is the standard the ADA Title II web rule adopts. PDF/UA is a technical standard for how a PDF is built inside. The two overlap heavily on tags, reading order, alt text, contrast and links, and PDF/UA adds rules that WCAG does not spell out. An automatic checker, such as PAC or veraPDF, verifies the parts a machine can check. A person has to decide the rest.

Document basics

  • The PDF is tagged. It is not just a picture of a page.
  • The document has a title, and the title shows in the window or tab, not just the file name.
  • The document language is set correctly. Passages in another language are marked.
  • It is not a scan. If it started as a scan, text recognition (OCR) was run and the result was checked.
  • Security settings do not block screen readers.

Structure and reading order

  • The reading order matches what a person would read, including across columns and sidebars.
  • Headings are tagged as headings, in order (level 1, then 2, and so on), not just made bold.
  • Lists are tagged as lists.
  • Repeating page elements, such as headers, footers and page numbers, are marked as artifacts so they are not read on every page.
  • Long documents have bookmarks that follow the headings.

Tables

  • Data tables are tagged as tables, with a header row, and header cells are marked as headers.
  • Tables are not used just for layout.
  • Merged or split cells have been checked, because they are a common source of errors.

Images and links

  • Images that carry meaning have a short, useful description (alt text).
  • Decorative images are marked as artifacts or have empty alt text.
  • Charts and diagrams have a text version of the point they make.
  • Link text says where the link goes. It is not “click here”.

Colour and text

  • Text has enough contrast against its background: at least 4.5 to 1 for normal text and 3 to 1 for large text.
  • Colour is not the only way to understand something, such as a status or a chart legend.
  • Text is real text, not an image of text.

Forms

  • Every form field has a label that a screen reader announces.
  • The tab order follows the order of the fields on the page.
  • Required fields and instructions are stated in text, not only by colour or position.

Check it

  • Run an accessibility checker and fix what it reports.
  • Listen to the first page or two with a screen reader, or read the tag tree in Acrobat.
  • Open the PDF zoomed to 200 percent and check that the text can still be read.
  • Ask someone who uses assistive technology to try a sample, when you can.

Where idioma.chat fits

pdf.idioma.chat repairs a PDF's structure so a screen reader can follow it, for $0.50 per page with your first 10 pages free. We test our results against PDF/UA with veraPDF, and some documents still need a person to review them. See what remediation costs and which PDFs Title II covers.

Sources

Related guides

See it on your own pages.

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PDF accessibility checklist for WCAG 2.1 AA and PDF/UA – idioma.chat