Audit Criteria — WCAG AA

In this tutorial, you will learn about Audit Criteria. We cover key concepts, practical examples, and best practices to help you master this topic.

WCAG AA includes all Level A and Level AA success criteria organized under four principles: Perceivable, Operable, Understandable, and Robust -- covering approximately 50 criteria that form the standard Compliance target for most Accessibility audits.

What You'll Learn

You will understand the key WCAG AA criteria evaluated in audits, how to test each criterion, and how to document compliance or non-compliance for audit reports.

Why It Matters

WCAG AA is the most common legal standard referenced in accessibility lawsuits and regulations including ADA, Section 508, and EN 301 549. Auditing against AA provides the strongest legal protection.

Real-World Use

An auditor evaluates a healthcare portal against WCAG AA. Most criteria pass, but 1.4.3 (Contrast Minimum) fails on secondary text, 2.4.3 (Focus Order) fails on the appointment booking flow, and 4.1.2 (Name, Role, Value) fails on custom date pickers.

WCAG AA Criteria Overview

flowchart TD
  A[WCAG AA] --> B[Perceivable]
  A --> C[Operable]
  A --> D[Understandable]
  A --> E[Robust]
  B --> B1[1.1.1 Non-text Content]
  B --> B2[1.2.x Captions/Media]
  B --> B3[1.3.x Adaptable]
  B --> B4[1.4.x Distinguishable]
  C --> C1[2.1.x Keyboard]
  C --> C2[2.4.x Navigable]
  C --> C3[2.5.x Input Modalities]
  D --> D1[3.1.x Readable]
  D --> D2[3.2.x Predictable]
  D --> D3[3.3.x Input Assistance]
  E --> E1[4.1.1 Parsing]
  E --> E2[4.1.2 Name, Role, Value]
  E --> E3[4.1.3 Status Messages]

Evaluating Criteria

Each criterion has specific test steps. Document pass/fail with evidence.

<!-- Criterion 1.1.1: Non-text Content -->
<img src="chart.png" alt=""> <!-- FAIL: missing alt text -->
<img src="decorative.png" alt="" role="presentation"> <!-- PASS: decorative -->
<img src="chart.png" alt="Bar chart showing Q4 revenue"> <!-- PASS: meaningful -->

<!-- Criterion 1.3.1: Info and Relationships -->
<p style="font-weight: bold; font-size: 24px;">Section Title</p> <!-- FAIL: should be <h2> -->
<h2>Section Title</h2> <!-- PASS: semantic heading -->

/* Criterion 1.4.3: Contrast Minimum */
.text-secondary { color: #888; } /* FAIL: 3.3:1 against white */
.text-secondary { color: #555; } /* PASS: 5.1:1 against white */

/* Criterion 2.4.7: Focus Visible */
*:focus { outline: none; } /* FAIL: no visible focus */
*:focus-visible { outline: 3px solid #0066cc; } /* PASS */

// Criterion 3.3.1: Error Identification
function validateForm() {
  const email = document.getElementById('email');
  if (!email.validity.valid) {
    // FAIL: no specific error message
    alert('Error in form');

    // PASS: specific error message with ID reference
    document.getElementById('email-error').textContent =
      'Please enter a valid email address';
  }
}

Common Mistakes

• Testing against WCAG 2.0 instead of 2.1 or 2.2
• Not documenting which version of WCAG was used
• Confusing Level A, AA, and AAA requirements
• Missing criteria that require manual evaluation
• Not providing evidence for pass/fail decisions
• Failing to check criteria interactions (e.g., contrast AND non-text contrast)
• Using outdated interpretations of criteria

Practice and Challenge

Practice 1: List all WCAG AA criteria for the Perceivable principle. Practice 2: Write a test procedure for criterion 2.4.3 (Focus Order). Practice 3: Determine if a criterion passes or fails given a code sample. Practice 4: Create a compliance checklist for all AA criteria. Practice 5: Identify which criteria require screen reader testing.

Challenge: Create a WCAG AA evaluation matrix with columns for each criterion, its POUR principle, testing method (automated/manual), typical failures, and an example pass/fail. Include all 50 criteria.

FAQ

Mini Project

Create a WCAG AA audit checklist in spreadsheet format. Include columns: criterion ID, principle, description, testing method, pass criteria, typical failures, and notes. Populate it with all AA criteria from WCAG 2.2.

What's Next

Automated Scan Tools covers the automated tools used in accessibility audits.