WCAG Level A vs AA vs AAA: Which Do You Need?

WCAG — the Web Content Accessibility Guidelines — divides its requirements into three conformance levels: A, AA, and AAA. If you have ever been told your site needs to be “WCAG compliant,” what that almost always means is WCAG 2.2 Level AA. But understanding why, and what separates the three levels, is essential for making good remediation and product decisions.

The Three Levels at a Glance

Level	Description	Legal threshold?
A	Minimum baseline — removes the most severe barriers	Rarely sufficient alone
AA	Standard compliance — the universal legal benchmark	Yes, in virtually all jurisdictions
AAA	Enhanced accessibility — the highest level of support	Not legally required; aspirational

Each level is cumulative. Achieving AA means satisfying all Level A and all Level AA criteria. Achieving AAA means satisfying all three levels.

Level A: The Baseline

Level A contains the success criteria that, if not met, make a product completely unusable for certain groups of people. These are not edge cases — they represent absolute blockers.

What Level A requires (selected examples):

1.1.1 Non-text Content — All images, icons, and media must have text alternatives (alt text)
1.3.1 Info and Relationships — Structure conveyed visually (headings, lists, tables) must also be available programmatically
2.1.1 Keyboard — Every function must be operable with a keyboard alone
2.4.1 Bypass Blocks — Users must be able to skip repetitive navigation (skip links)
3.1.1 Language of Page — The page language must be set in the HTML lang attribute
4.1.1 Parsing — (Obsolete in WCAG 2.2; always considered satisfied)
3.2.6 Consistent Help (added in 2.2) — Help mechanisms must appear in consistent positions
3.3.7 Redundant Entry (added in 2.2) — Information entered earlier in a session must not be required again

Is Level A enough? No. Level A alone will not satisfy any major accessibility law. It is the floor, not the target.

Level AA: The Legal Standard

Level AA is where the law draws the line. It is referenced by:

ADA (Americans with Disabilities Act) — informal DOJ guidance and court decisions consistently point to WCAG 2.x AA
European Accessibility Act (EAA) — requires compliance with EN 301 549, which references WCAG 2.2 AA
EU Web Accessibility Directive — mandates WCAG 2.1 AA for public sector bodies (updating to 2.2)
UK PSBAR — requires WCAG 2.1 AA for UK public sector websites
Section 508 (US Federal) — references WCAG 2.0 AA as the baseline
Accessibility for Ontarians with Disabilities Act (AODA) — requires WCAG 2.0 Level AA

What Level AA adds on top of A (selected examples):

1.4.3 Contrast (Minimum) — Text must have a contrast ratio of at least 4.5:1 (3:1 for large text)
1.4.4 Resize Text — Text must remain readable when scaled to 200% without loss of content
1.4.10 Reflow (added in 2.1) — Content must not require horizontal scrolling at 320px width
1.4.11 Non-text Contrast (added in 2.1) — UI components and focus indicators must meet 3:1 contrast
1.4.12 Text Spacing (added in 2.1) — Content remains usable when letter/line/word spacing is overridden
2.4.7 Focus Visible — Keyboard focus indicators must be visible
2.4.11 Focus Not Obscured (added in 2.2) — Focused elements must not be entirely hidden by sticky headers/overlays
2.4.13 Focus Appearance (added in 2.2) — Focus indicators must meet minimum size and contrast thresholds
2.5.3 Label in Name (added in 2.1) — Visible labels must be included in accessible names
2.5.8 Target Size (Minimum) (added in 2.2) — Interactive targets must be at least 24×24 CSS pixels
3.3.8 Accessible Authentication (added in 2.2) — Login flows must not rely on cognitive function tests (CAPTCHAs)

Level AA is achievable through engineering and design — it does not require extraordinary effort, but it does require deliberate attention throughout the product development process.

Level AAA: The Gold Standard

Level AAA contains the most demanding criteria. They address scenarios where even small barriers have a significant impact on users with severe or multiple disabilities. W3C explicitly states that it may not be possible to satisfy all AAA criteria for all content.

What Level AAA adds (selected examples):

1.2.6 Sign Language (Prerecorded) — Sign language interpretation must be provided for prerecorded audio content
1.4.6 Contrast (Enhanced) — Contrast ratio must be at least 7:1 for normal text (4.5:1 for large text)
2.1.3 Keyboard (No Exception) — Every function must be keyboard-operable with no exceptions at all
2.2.3 No Timing — No time limits are permitted whatsoever
2.4.12 Focus Not Obscured (Enhanced) — Focused elements must be fully visible (not just partially)
2.4.9 Link Purpose (Link Only) — Every link’s purpose must be clear from the link text alone, without surrounding context
3.1.5 Reading Level — Content is available at lower secondary reading level or a simplified alternative is provided
3.3.6 Error Prevention (All) — All submissions (not just legal/financial) must be reversible, checked, or confirmed

Should you pursue AAA? Many organisations do selectively. For example, a bank serving elderly customers might prioritise 1.4.6 Enhanced Contrast. A government service might target 3.1.5 Reading Level. But pursuing AAA across an entire public-facing website is rare and not legally required anywhere in the world.

Common Misconceptions

“We passed an automated scan, so we’re AA compliant.” Automated tools catch around 30–40% of WCAG issues. Many AA criteria — keyboard navigation, focus management, meaningful reading order, accessible authentication — can only be verified through manual testing or evaluation with assistive technologies.

“We need AAA for government contracts.” Government procurement frameworks (Section 508, EN 301 549) require AA, not AAA. AAA may appear in individual contract specifications, but it is not the baseline.

“We met AA three years ago so we’re still compliant.” WCAG 2.2 added new AA criteria. If your last audit was against WCAG 2.0 or 2.1, you need a gap assessment against the 2.2 additions — particularly focus appearance, focus not obscured, target size, and accessible authentication.

“Level A is enough because we’re a small business.” Size does not determine the applicable standard. The ADA applies to places of public accommodation regardless of size. The EAA applies to private sector businesses over a certain threshold regardless of size. Level A alone will not satisfy either.

Choosing Your Target Level

For the vast majority of organisations, the answer is straightforward: WCAG 2.2 Level AA is your target.

If you serve public sector clients in the EU or UK, this is a legal obligation. If you operate consumer-facing digital products in the EU (ecommerce, banking, transport, telecom), the EAA makes it mandatory from June 2025. If you have US-based users, ADA case law increasingly treats WCAG 2.x AA as the expected standard.

The path to AA:

Run automated scans to identify clear failures (contrast, missing alt text, missing labels)
Conduct a manual audit covering keyboard navigation, screen reader behaviour, and WCAG 2.2-specific criteria
Fix issues by priority — critical blockers first, then AA gaps
Publish an accessibility statement declaring your conformance level and known limitations
Set up continuous monitoring to catch regressions as your site evolves

Reaching Level A first, then closing the remaining AA gaps in a second phase, is a valid sequenced approach for teams with limited capacity. Just ensure the AA gaps have a firm remediation deadline — Level A alone is not a defensible compliance position.

WCAG’s three levels exist not as a bureaucratic ladder but as a practical acknowledgment that accessibility is a spectrum. Level A removes walls. Level AA makes the experience genuinely usable. Level AAA pushes toward inclusion for every user in every situation. Your legal obligation is AA — but your users benefit from everything beyond it.