WCAG (Web Content Accessibility Guidelines) is a set of W3C recommendations for making web content more accessible to people with disabilities, organized around four principles — Perceivable, Operable, Understandable, and Robust — with testable success criteria at conformance levels A, AA, and AAA.
WCAG
WCAG (Web Content Accessibility Guidelines) is the W3C’s standard for making web content accessible to people with disabilities. It is organized around four principles — content must be Perceivable, Operable, Understandable, and Robust (POUR) — expressed as testable success criteria grouped into conformance levels A, AA, and AAA. WCAG 2.1 and 2.2 are the widely referenced versions, and they underpin legal accessibility requirements in many jurisdictions.
- POUR principles - Perceivable, Operable, Understandable, and Robust, the four pillars every guideline hangs from.
- Conformance levels A / AA / AAA - Tiers of increasing strictness, with AA the common legal and procurement target.
- Testable success criteria - Concrete, checkable requirements rather than vague goals, which makes conformance auditable.
- Legal and procurement baseline - Referenced by regulations like the ADA, Section 508, and the European Accessibility Act.
WCAG is aimed at web content rather than APIs directly, but it matters across an API operation in ways that are easy to overlook: developer portals, documentation, dashboards, and API consoles are all web content that must meet these guidelines, and public-sector API programs are increasingly held to WCAG conformance by law. Treating accessibility as a governance requirement — measurable, tiered, and auditable like any other policy — is the practical way it shows up in the work I do, and it’s a reminder that the human-facing surface of an API is part of the product, not an afterthought.
Industry: Accessibility
Governed by these regulations
A standard is the machine-readable contract; a regulation is the law that requires it. These are the regulations that mandate or drive this standard, catalogued at regulations.apievangelist.com.
Americans with Disabilities Act Title III, as applied to websites and apps
No US regulation names a standard for private entities, but settlements, consent decrees and expert testimony converge on WCAG 2.1 AA — a de facto standard that was never adopted as one.
Accessibility for Ontarians with Disabilities Act (S.O. 2005, c. 11)
The Integrated Accessibility Standards Regulation names WCAG 2.0 Level AA directly, which is what distinguishes AODA from the US approach of litigating it case by case.
European Accessibility Act (EAA)
EN 301 549, the European standard the EAA leans on, incorporates WCAG success criteria — which is how a W3C guideline acquired the force of EU product law.
Section 508 of the Rehabilitation Act
Section 508's refreshed standards incorporate WCAG 2.0 Level AA by reference for US federal procurement.
