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WCAG Conformance Levels Explained: A, AA, and AAA Requirements

TestParty

August 2, 2025

Understanding Conformance Levels
Level A Requirements
Level AA Requirements
Level AAA Requirements
Choosing Your Target Level
Conformance Requirements
Testing for Conformance
FAQ Section
Key Takeaways
Conclusion

WCAG conformance levels (A, AA, and AAA) represent increasing degrees of accessibility. Level A provides minimum accessibility, Level AA is the widely-adopted legal standard, and Level AAA represents enhanced accessibility for specialized contexts. Understanding these levels is essential for setting compliance targets and prioritizing remediation efforts.

Most legal requirements—including ADA expectations, Section 508, and the European Accessibility Act—reference WCAG 2.1 Level AA as the standard. This guide explains what each level requires and how to approach conformance.

Q: Which WCAG conformance level is legally required?

A: WCAG 2.1 Level AA is the most commonly referenced legal standard. The DOJ's 2024 rule specifies WCAG 2.1 AA for covered entities. Most ADA settlements and Section 508 requirements target Level AA. Level A is minimum baseline; Level AAA is aspirational for most organizations.

Understanding Conformance Levels

How Levels Work

WCAG success criteria are assigned to one of three levels:

Level A: Most basic accessibility requirements. Failure at this level creates fundamental barriers that prevent some users from accessing content at all.

Level AA: Standard accessibility requirements. Addresses the most significant and common barriers for the widest range of users.

Level AAA: Enhanced accessibility requirements. Provides the highest level of accessibility but may not be achievable for all content types.

Cumulative Requirements

Conformance levels are cumulative:

Level A conformance: Meet all Level A criteria
Level AA conformance: Meet all Level A AND all Level AA criteria
Level AAA conformance: Meet all Level A, Level AA, AND Level AAA criteria

You cannot claim Level AA conformance without first meeting all Level A requirements.

Level A Requirements

Level A represents the minimum accessibility threshold. Failure to meet Level A criteria typically creates barriers that completely block access for some users.

Key Level A Success Criteria

1.1.1 Non-text Content All non-text content has a text alternative that serves equivalent purpose.

<!-- Images need alt text -->
<img src="product.jpg" alt="Blue Nike running shoes">

1.3.1 Info and Relationships Information, structure, and relationships conveyed visually are programmatically determinable.

<!-- Use proper heading hierarchy -->
<h1>Product Name</h1>
<h2>Description</h2>
<h3>Features</h3>

2.1.1 Keyboard All functionality is operable via keyboard interface.

<!-- Use native elements or add keyboard support -->
<button onclick="addToCart()">Add to Cart</button>

2.4.1 Bypass Blocks Mechanism to bypass blocks of content repeated on multiple pages.

<a href="#main-content" class="skip-link">Skip to main content</a>

3.1.1 Language of Page Default human language of page can be programmatically determined.

<html lang="en">

4.1.1 Parsing (Removed in WCAG 2.2) No longer required—browsers handle parsing robustly.

4.1.2 Name, Role, Value All UI components have accessible name, role, and state.

<button aria-expanded="false" aria-controls="menu">
  Toggle Menu
</button>

Level A Violation Impact

Level A failures create severe barriers:

Images without alt text are invisible to blind users
Keyboard-inaccessible elements completely block keyboard users
Missing labels leave form fields unusable with screen readers
Auto-playing audio with no controls disrupts all screen reader users

If you're not meeting Level A, start here. These are fundamental barriers affecting core functionality.

Level AA Requirements

Level AA is the standard compliance target—what courts, regulations, and best practices expect. Level AA criteria address significant barriers that affect many users.

Key Level AA Success Criteria

1.4.3 Contrast (Minimum) Text has at least 4.5:1 contrast ratio (3:1 for large text).

/* Minimum contrast */
.text { color: #767676; background: #ffffff; } /* 4.5:1 */

1.4.4 Resize Text Text can be resized up to 200% without loss of content or functionality.

1.4.5 Images of Text Use actual text instead of images of text (with exceptions for logos, customizable images).

2.4.6 Headings and Labels Headings and labels describe topic or purpose.

<h2>Shipping Information</h2> <!-- Descriptive -->
<h2>Section 2</h2> <!-- Not descriptive -->

2.4.7 Focus Visible Keyboard focus indicator is visible.

:focus {
  outline: 3px solid #005fcc;
  outline-offset: 2px;
}

3.3.3 Error Suggestion If error is detected and suggestions known, provide them.

<span class="error">
  Please enter a valid email (example: name@domain.com)
</span>

3.3.4 Error Prevention (Legal, Financial, Data) For pages involving legal, financial, or data submissions: reversible, verified, or confirmed before final.

WCAG 2.1 Level AA Additions

WCAG 2.1 added mobile-focused criteria at Level AA:

1.3.4 Orientation Content not restricted to single display orientation.

1.3.5 Identify Input Purpose Input purpose can be programmatically determined (autocomplete attributes).

<input type="email" autocomplete="email">

1.4.10 Reflow Content reflows without horizontal scrolling at 320px width.

1.4.11 Non-text Contrast UI components and graphics have 3:1 contrast ratio.

1.4.12 Text Spacing Content works with increased line height, paragraph spacing, letter spacing, word spacing.

1.4.13 Content on Hover or Focus Additional content triggered by hover/focus is dismissible, hoverable, and persistent.

WCAG 2.2 Level AA Additions

WCAG 2.2 added criteria particularly relevant to cognitive accessibility:

2.4.11 Focus Not Obscured (Minimum) Focused element not entirely hidden by author-created content.

2.5.7 Dragging Movements Functionality using dragging has single-pointer alternative.

2.5.8 Target Size (Minimum) Touch targets at least 24×24 CSS pixels.

3.3.7 Redundant Entry Information previously entered is auto-populated or available for selection.

Level AAA Requirements

Level AAA provides enhanced accessibility but isn't typically required for full-site conformance. Some criteria may not be achievable for all content.

Key Level AAA Success Criteria

1.4.6 Contrast (Enhanced) 7:1 contrast ratio for text (4.5:1 for large text).

1.4.8 Visual Presentation User can select foreground/background colors, control width, line spacing, text alignment, paragraph spacing.

2.1.3 Keyboard (No Exception) All functionality keyboard operable—no exceptions.

2.2.3 No Timing Timing not essential part of activity (except real-time events).

2.4.9 Link Purpose (Link Only) Link purpose determinable from link text alone.

<a href="/shipping">View our shipping policy</a> <!-- AAA compliant -->
<a href="/shipping">Click here</a> <!-- Not AAA compliant -->

3.1.3 Unusual Words Mechanism to identify definitions of unusual words or jargon.

3.1.5 Reading Level When text requires more than lower secondary education reading level, supplemental content or accessible version available.

Why Full AAA Conformance Is Rare

WCAG itself states: "It is not recommended that Level AAA conformance be required as a general policy for entire sites because it is not possible to satisfy all Level AAA Success Criteria for some content."

Challenges:

3.1.5 Reading Level may be impossible for technical content
2.2.3 No Timing prevents time-limited legitimate uses
Some criteria require significant content restructuring

Appropriate AAA targets:

Specific pages (help content, key landing pages)
Specific criteria (enhanced contrast, better link text)
Specialized applications for users with specific disabilities

Choosing Your Target Level

Level AA: The Standard

Target Level AA for:

Legal compliance (ADA, Section 508, EAA)
Most commercial websites
E-commerce sites
Corporate websites
Web applications

Why Level AA:

Meets regulatory expectations
Achievable for all content types
Addresses most significant barriers
Reasonable implementation effort

Level A Only: Minimum Viable

When Level A alone might apply:

Legacy systems scheduled for replacement
Internal tools with limited user base
Temporary while working toward AA

Caution: Level A alone doesn't meet most legal requirements and leaves significant barriers unaddressed.

Selective Level AAA

Apply AAA criteria where beneficial:

Enhanced contrast throughout
Better link text practices
Sign language for videos (where audience benefits)
Reading level considerations for public-facing content

Conformance Requirements

Full Conformance

To claim conformance at any level:

All applicable criteria met for that level
Entire page conforms (not just parts)
No interference with accessibility of other content
Technology relied upon supports accessibility

Partial Conformance

When full conformance isn't possible:

Partial conformance due to third-party content: Pages with third-party content can claim partial conformance if they:

Conform when third-party content is removed
Third-party content isn't under author's control
Author has made efforts to address barriers

Conformance statement:

This page partially conforms to WCAG 2.1 Level AA.
Third-party advertising and embedded social media
content may not fully conform.

Testing for Conformance

Automated Testing Coverage

TestParty and similar tools can automatically check many criteria:

Automatically detectable:

Missing alt attributes (1.1.1 partial)
Color contrast failures (1.4.3)
Missing form labels (1.3.1, 3.3.2)
Missing language declaration (3.1.1)
Keyboard trap detection (2.1.2 partial)
Heading hierarchy (1.3.1)

Require manual verification:

Alt text quality/accuracy (1.1.1)
Meaningful headings (2.4.6)
Keyboard operability (2.1.1)
Focus visibility adequacy (2.4.7)
Error suggestion quality (3.3.3)

Manual Testing Requirements

For each conformance level, manual testing should verify:

Content works with keyboard only
Screen reader announces correctly
Focus indicators visible
Zoom/reflow works at 200%/400%
Dynamic content accessible

FAQ Section

Q: Can I claim Level AA if I meet most but not all criteria?

A: No. Conformance requires meeting all applicable criteria at that level. You can claim partial conformance with documented exceptions, but not full Level AA conformance with criteria unmet.

Q: Does my whole site need to conform?

A: Each page is evaluated separately for conformance. However, legal requirements typically expect your entire website to meet standards. Non-conforming pages create liability.

Q: What's the difference between WCAG 2.0, 2.1, and 2.2 AA?

A: Each version adds criteria. WCAG 2.1 AA includes everything in 2.0 AA plus mobile-focused additions. WCAG 2.2 AA adds cognitive accessibility criteria. Later versions are backward-compatible—meeting 2.2 AA means you meet 2.0 and 2.1 AA.

Q: Should e-commerce sites target AAA?

A: Target AA as your baseline (legal standard). Implement AAA criteria where practical—enhanced contrast, descriptive link text, reduced redundant entry. Full AAA conformance isn't typical or expected.

Q: How do I know which success criteria apply?

A: Criteria apply if the relevant content type exists. No videos? Video criteria don't apply. No forms? Form criteria don't apply. Apply all criteria relevant to your content.

Key Takeaways

Level AA is the legal standard. DOJ, Section 508, and most regulations reference WCAG 2.1/2.2 Level AA.

Levels are cumulative. AA requires meeting all A and AA criteria. AAA requires A, AA, and AAA.

Level A failures are severe. They completely block access for some users. Fix these first.

Full AAA isn't expected for entire sites but applying selective AAA criteria improves accessibility.

Conformance means 100%. You can't claim AA with criteria unmet. Use partial conformance statements for known limitations.

WCAG 2.2 AA is current best practice. It includes mobile and cognitive accessibility improvements.

Conclusion

Understanding WCAG conformance levels helps you set appropriate targets and prioritize remediation. Level AA is the standard most organizations should target—it's what legal requirements expect and what provides meaningful accessibility for users with disabilities.

TestParty helps organizations achieve WCAG 2.2 AA conformance through automated detection and source code remediation. For e-commerce sites, this means fixing the barriers that affect customers and create legal exposure—at the level courts and regulations expect.

Ready to assess your conformance level? Get a free accessibility scan to see how your site measures against WCAG AA standards.

TestParty's content team produced this article using AI-powered research tools combined with our expertise in automated accessibility testing. The guidance here reflects current best practices but shouldn't substitute for professional legal counsel on ADA or WCAG compliance matters.

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