WCAG 2.0 vs 2.1 vs 2.2 vs 3.0 — what actually changed

Every time W3C publishes a new WCAG version, the same questions appear: do I need to update? What changed? Is the old version still valid? Here is a clear, version-by-version breakdown.

The key rule: backwards compatibility

Every WCAG 2.x release is a strict superset of the previous one. New criteria are added, but existing criteria are never changed or reworded (with one exception in 2.2 — more on that below). This means:

• A site conforming to WCAG 2.2 AA automatically conforms to 2.1 AA and 2.0 AA.
• A site conforming to WCAG 2.0 AA does not automatically conform to 2.1 or 2.2 — the newer criteria may not be met.

This is by design. Organisations that invested in 2.0 conformance did not have their work invalidated when 2.1 arrived.

WCAG 2.0 (December 2008)

The foundation. WCAG 2.0 introduced the structure that all subsequent versions follow: four principles (POUR), testable success criteria at three levels (A, AA, AAA), and a separation between normative criteria and informative techniques.

What it established:

• 61 success criteria across 12 guidelines.
• Technology-neutral language — designed to apply to web content regardless of the underlying technology.
• The conformance model still used today: five conformance requirements, including full-page and process-level conformance.

What it lacked:

• No specific criteria for mobile interaction (touchscreens, small viewports).
• Limited coverage of low-vision needs beyond contrast and text resizing.
• No criteria addressing cognitive accessibility in a meaningful way.

Legal status: Still the baseline referenced by Section 508 in the US. Some older national laws in Europe also reference 2.0 specifically.

WCAG 2.1 (June 2018)

The mobile and low-vision update. WCAG 2.1 added 17 new success criteria — 5 at Level A, 7 at Level AA, and 5 at Level AAA — addressing gaps identified after a decade of smartphones, tablets, and evolving assistive technology.

Key additions at AA (the level most laws require):

Criterion	What it requires
1.3.4 Orientation	Content is not locked to a single display orientation (portrait/landscape)
1.3.5 Identify Input Purpose	Input fields for personal data (name, email, address) identify their purpose programmatically
1.4.10 Reflow	Content reflows to a single column at 320px width without horizontal scrolling
1.4.11 Non-text Contrast	UI components and graphical objects have a 3:1 contrast ratio against adjacent colours
1.4.12 Text Spacing	Content remains functional when users override line height, letter spacing, word spacing, and paragraph spacing
1.4.13 Content on Hover or Focus	Additional content triggered by hover or focus can be dismissed, hovered over, and persists until dismissed
4.1.3 Status Messages	Status messages (e.g. “item added to cart”) are programmatically conveyed to assistive technology without receiving focus

Key additions at A:

Criterion	What it requires
2.1.4 Character Key Shortcuts	Single-character keyboard shortcuts can be remapped or disabled
2.5.1 Pointer Gestures	Multi-point or path-based gestures have single-pointer alternatives
2.5.2 Pointer Cancellation	Actions fire on up-event, not down-event, and can be aborted
2.5.3 Label in Name	The accessible name of a component contains its visible label text
2.5.4 Motion Actuation	Functionality triggered by device motion (shake, tilt) has a UI alternative

Why it matters: EN 301 549 — the harmonised standard for both the EU Web Accessibility Directive and the European Accessibility Act — references WCAG 2.1 AA. This is the legal compliance target for most European organisations.

WCAG 2.2 (October 2023)

The cognitive and motor accessibility update. WCAG 2.2 added 9 new success criteria and removed one — the first and only removal in WCAG 2.x history.

What was removed:

4.1.1 Parsing — originally required valid HTML to prevent assistive technology from misinterpreting markup. Modern browsers and AT handle parsing errors reliably, making this criterion obsolete. If you are studying older materials, note that this criterion no longer exists in 2.2.

Key additions at AA:

Criterion	What it requires
2.4.11 Focus Not Obscured (Minimum)	Focused elements are not entirely hidden behind sticky headers, footers, or other overlapping content
2.4.13 Focus Appearance	Focus indicators meet minimum size and contrast requirements
2.5.7 Dragging Movements	Functionality that uses dragging has a single-pointer alternative (no drag required)
2.5.8 Target Size (Minimum)	Interactive targets are at least 24×24 CSS pixels, with exceptions for inline links and constrained layouts
3.2.6 Consistent Help	Help mechanisms (chat, phone, FAQ) appear in the same relative location across pages
3.3.7 Redundant Entry	Information previously provided by the user is auto-populated or available for selection — users are not asked to re-enter the same data

Key additions at A:

Criterion	What it requires
3.3.8 Accessible Authentication (Minimum)	Cognitive function tests (e.g. remembering a password, solving a puzzle) are not required unless an alternative is provided
3.3.9 Accessible Authentication (Enhanced)	AAA version — no cognitive function test at all, including object recognition

Key addition at AAA:

Criterion	What it requires
2.4.12 Focus Not Obscured (Enhanced)	Focused elements are fully visible, not even partially obscured

Why it matters: WCAG 2.2 is the current stable version and the best target for new projects. While no major law references 2.2 specifically yet, conforming to 2.2 AA automatically satisfies 2.1 AA requirements — so you meet every current legal framework and go beyond it.

WCAG 3.0 (Working Draft)

WCAG 3.0 — formally titled W3C Accessibility Guidelines (dropping “Web Content” from the name) — is a complete redesign, not an incremental update. It is still in development and is not a finished standard.

What is changing:

• New conformance model. The A/AA/AAA levels are replaced by a scoring system with bronze, silver, and gold outcomes. Partial credit is possible — a site can score well overall even if a few edge cases remain.
• Broader scope. Covers web, native apps, documents, XR/VR, and emerging technologies. The name change reflects this.
• New testing methods. Combines automated tests, manual evaluation, and user testing into a single framework.
• Outcome-based structure. Instead of success criteria grouped under principles, guidelines are organised around user outcomes.

What is NOT changing:

• The four POUR principles remain as a conceptual foundation.
• The intent behind existing 2.x criteria is carried forward, though the wording and testing methods will differ.

Current status (mid-2026): Working Draft. No law references it. No conformance claims can be made against it. The timeline for a final recommendation is uncertain — most estimates place it several years out.

For the CPACC exam: know that WCAG 3.0 exists, understand its high-level goals (broader scope, scoring model, outcome-based), and be clear that it is not yet a finished standard. You do not need to study its specific guidelines or scoring rules.

Which version should you target?

Context	Target	Why
New project (any sector)	WCAG 2.2 AA	Current stable version; satisfies all existing legal requirements
EU compliance (EAA / Web Accessibility Directive)	WCAG 2.1 AA minimum	EN 301 549 references 2.1; targeting 2.2 exceeds the requirement
US federal (Section 508)	WCAG 2.0 AA minimum	Still the legal reference; agencies moving to 2.1/2.2 in practice
CPACC exam preparation	WCAG 2.2 as reference	Study the current version; understand what changed in each iteration
Existing site maintaining conformance	At least match your current claim	If you claim 2.1 AA, maintain it; upgrade to 2.2 when practical

Version comparison at a glance

	WCAG 2.0	WCAG 2.1	WCAG 2.2	WCAG 3.0
Released	2008	2018	2023	In progress
Total criteria	61	78	86 (minus 4.1.1)	TBD
Mobile support	Limited	Strong	Strong	Expanded
Cognitive accessibility	Minimal	Improved	Significantly expanded	Core focus
Conformance model	A / AA / AAA	A / AA / AAA	A / AA / AAA	Bronze / Silver / Gold
Legal references	Section 508, some older EU laws	EN 301 549, EAA	None specifically yet	None (not finished)
Status	Superseded	Current legal baseline (EU)	Current stable recommendation	Working Draft

The safest, most future-proof approach: build to WCAG 2.2 AA, stay aware of 3.0’s direction, and do not lose sleep over it until it becomes a Recommendation.