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What is WCAG?
WCAG stands for Web Content Accessibility Guidelines. Most US rules currently point to WCAG 2.1, published June 5, 2018.
WCAG has three levels:
- Level A — the bare minimum. Skipping these breaks accessibility entirely for some users.
- Level AA — what almost every law and regulation actually requires. This is the practical baseline.
- Level AAA — the highest bar. Mostly aspirational; few documents meet it everywhere.
"WCAG compliance" usually means Level AA.
The WCAG success criteria that matter for PDFs
About 20 WCAG 2.1 AA criteria are directly relevant to PDFs. The most important:
- 1.1.1 Non-text Content — Every meaningful image needs alt text. Decorative images need to be marked as decoration so screen readers skip them.
- 1.3.1 Info and Relationships — The PDF's structure needs to be tagged correctly. Headings tagged as headings, lists as lists, tables as tables. Visual styling alone isn't enough.
- 1.3.2 Meaningful Sequence — The reading order has to make sense. A screen reader should read the page in the order a sighted person would.
- 1.4.3 Contrast (Minimum) — Body text needs at least 4.5:1 contrast against its background; large text needs 3:1.
- 1.4.4 Resize Text — Text has to remain readable when zoomed up to 200%.
- 2.4.2 Page Titled — The PDF needs a title in its metadata, and the viewer should display it.
- 2.4.6 Headings and Labels — Headings must describe what they introduce; form labels must describe what each field is for.
- 3.1.1 Language of Page — The document's primary language has to be set in metadata so screen readers pronounce it correctly.
- 3.3.2 Labels or Instructions — Form fields need clear labels or instructions.
- 4.1.2 Name, Role, Value — Form fields, links, and interactive elements need to be properly identified to assistive technology.
These cover the bulk of PDF accessibility risk.
WCAG vs PDF/UA — how they fit together
WCAG sets the accessibility goals. PDF/UA-1 (ISO 14289-1:2014) translates those goals into PDF tags, structure, metadata, and reading order.
So:
- WCAG 2.1 AA tells you what needs to be accessible.
- PDF/UA-1 tells you how to make a PDF do it — exact tag types, attribute requirements, metadata rules.
- Section 508 references PDF/UA-1 directly. ADA Title II requires WCAG 2.1 AA but PDF/UA-1 is the practical path to demonstrate it for PDF files.
For more on the PDF-specific standards, see our PDF/UA & WTPDF guide.
WCAG 2.1 vs WCAG 2.2 — which one applies?
WCAG 2.2 was published October 5, 2023 and is backward compatible. US PDF compliance targets still point to WCAG 2.1 AA:
- ADA Title II requires WCAG 2.1 AA, not 2.2.
- Section 508's current text references WCAG 2.0 AA, but WCAG 2.1 AA is the standard the federal government actually uses today.
- Most state procurement and accessibility laws point to WCAG 2.1.
Bottom line: meet WCAG 2.1 AA today; WCAG 2.2 is a useful future-facing target.
Who needs WCAG 2.1 AA?
US state and local governments
Required by ADA Title II. Deadlines: April 26, 2027 for 50,000+ entities and April 26, 2028 for smaller entities and special districts. See our ADA Title II guide.
US federal agencies and their contractors
Required by Section 508. PDFs need PDF/UA-1 conformance specifically. See our Section 508 guide.
Universities, colleges, and K-12 districts
Public institutions are covered by ADA Title II. Private institutions are increasingly subject to ADA Title III lawsuits over inaccessible PDFs.
Most public-facing businesses
WCAG 2.1 AA is the safest target for reducing PDF accessibility litigation risk.
Primary sources to verify
Use these standards references when you review WCAG and PDF accessibility requirements.
How ADAComply handles WCAG 2.1 AA
ADAComply is designed to remediate PDFs to WCAG 2.1 AA, PDF/UA-1, PDF/UA-2, and WTPDF. Standard-layout pages move through the remediation pipeline, uncertain pages route to specialists, and reports stay in the dashboard.
Send your site for a free dashboard audit of public PDFs.
Frequently asked questions
What is WCAG 2.1?
The Web Content Accessibility Guidelines, version 2.1 — published by the W3C in June 2018. It defines how digital content should work for people with disabilities. Three levels: A, AA, AAA. Most laws target Level AA.
Does WCAG apply to PDFs?
Yes. WCAG was written for the web but applies to any digital document. For PDFs, the practical path is to meet PDF/UA-1, which translates WCAG requirements into PDF's tagging model.
Should I target WCAG 2.1 or 2.2?
For 2026, WCAG 2.1 AA. That's what ADA Title II and Section 508 require. WCAG 2.2 is fine but not required, and meeting 2.2 automatically means you meet 2.1.
Which WCAG criteria matter most for PDFs?
1.1.1 (alt text), 1.3.1 (proper tagging), 1.3.2 (reading order), 1.4.3 (color contrast), 2.4.6 (descriptive headings), 3.1.1 (language metadata), and 4.1.2 (form field labels). About 20 of WCAG's 50 AA criteria apply to PDFs at all.
Is meeting PDF/UA-1 enough for WCAG?
For standard PDF remediation workflows, yes. PDF/UA-1 covers the structural and semantic side of WCAG. Judgment-based items such as meaningful alt text and color independence should still be reviewed when the workflow flags uncertainty.