What is WCAG — and which version matters now

If you are preparing for an accessibility certification or working on compliance, WCAG is the document you will spend the most time with. Here is what it actually is, how it works, and why people keep arguing about version numbers.

WCAG in one paragraph

WCAG stands for Web Content Accessibility Guidelines. It is a technical standard published by the W3C (World Wide Web Consortium) — the same organisation that maintains HTML and CSS. WCAG defines how to make web content perceivable, operable, understandable, and robust for people with disabilities. It is not a law itself, but most accessibility laws around the world reference it directly.

How WCAG is structured

WCAG follows a clean hierarchy. Understanding it makes the entire document manageable:

1. Principles — the four foundations, known as POUR: Perceivable, Operable, Understandable, Robust.
2. Guidelines — under each principle, a handful of general goals (e.g. “provide text alternatives for non-text content”).
3. Success Criteria — testable statements at three conformance levels: A (minimum), AA (the standard most laws require), and AAA (aspirational for most sites).
4. Sufficient and Advisory Techniques — practical ways to meet each criterion. These are informative, not normative — they show how, but you can meet the criterion differently if you achieve the same outcome.

“Success criteria are the rules. Techniques are the recipes. You can cook the dish your own way as long as it passes the taste test.”

Which versions exist

Version	Released	Key milestone
WCAG 1.0	1999	First standard — largely historical now
WCAG 2.0	2008	Technology-neutral rewrite; still the legal baseline in some jurisdictions
WCAG 2.1	2018	Added criteria for mobile, low vision, and cognitive accessibility
WCAG 2.2	2023	Added criteria for cognitive and motor accessibility; removed 4.1.1 Parsing
WCAG 3.0	In development	Completely new scoring model — not yet a finished standard

Each 2.x version is backwards-compatible: everything in 2.0 is in 2.1, and everything in 2.1 is in 2.2. A site that conforms to 2.2 AA automatically conforms to 2.1 AA and 2.0 AA as well.

Which version matters right now

For the CPACC exam, the Body of Knowledge references WCAG in its current stable form. You should study with WCAG 2.2 as your reference and understand what changed from 2.1. The exam does not go deep into individual success criteria — it tests whether you understand the structure, the principles, and the reasoning behind levels.

For European compliance, EN 301 549 (the harmonised standard for the EU Web Accessibility Directive and the EAA) references WCAG 2.1 AA as the conformance target. Organisations adopting 2.2 get full coverage and go beyond the minimum requirement.

For US federal compliance, Section 508 currently maps to WCAG 2.0 AA, though agencies are increasingly moving to 2.1 or 2.2 in practice.

The safe default: target WCAG 2.2 AA. You satisfy every current legal framework and prepare for the direction all of them are heading.

What about WCAG 3.0?

WCAG 3.0 (working title: W3C Accessibility Guidelines) is a ground-up redesign. It replaces the A/AA/AAA conformance levels with a scoring model, broadens scope beyond web content, and introduces new testing methods. As of mid-2026, it remains a Working Draft — it is not a finished standard and no law references it yet.

You should know it exists and what it aims to change, but you do not need to study its criteria for the CPACC exam or current compliance work.

Common misconceptions

“WCAG only applies to websites.” Technically the name says “Web Content”, but WCAG 2.x criteria are written to be technology-neutral. Laws like the EAA apply them to mobile apps, self-service terminals, and e-books. In practice, WCAG is the accessibility standard for almost all digital products.

“Level AAA means fully accessible.” AAA is not a higher grade of the same thing — some AAA criteria are so strict that meeting all of them is impractical for many types of content (e.g. sign-language interpretation for all video). The standard itself says full AAA conformance is “not recommended as a general policy.”

“If I follow the techniques, I conform.” Techniques are sufficient, not necessary. You can follow a technique and still fail the success criterion if you missed the point. Conformance is measured against the criterion itself, not against a checklist of techniques.

How this connects to your CPACC preparation

The CPACC exam does not ask you to recite success criteria by number. It asks whether you understand:

• why the POUR principles exist and what each one protects,
• how conformance levels work and what “AA” means in a real project,
• which version of WCAG a given law references,
• the difference between normative criteria and informative techniques.

If you can explain those four points to a non-technical colleague in plain language, you are in good shape for the WCAG portion of the exam.