Accessibility Testing

Consolidated: For comprehensive WCAG auditing with multi-tool testing (axe-core + pa11y + Lighthouse), video accessibility, and remediation, prefer /a11y-ally. This skill provides a quick reference card for basic accessibility testing patterns.

Browser engine

Browser-driven a11y checks should go through the qe-browser fleet skill. vibium a11y-tree --json returns the full accessibility tree without visual rendering — feed it into axe-core via vibium eval --stdin for ruleset enforcement. See .claude/skills/qe-browser/SKILL.md.

<default_to_action> When testing accessibility or ensuring compliance:

1. APPLY POUR principles: Perceivable, Operable, Understandable, Robust
2. TEST with keyboard-only navigation (Tab, Enter, Escape)
3. VALIDATE with screen readers (VoiceOver, NVDA, JAWS)
4. CHECK color contrast (4.5:1 for text, 3:1 for large text)
5. AUTOMATE with axe-core, integrate in CI/CD pipeline

Quick A11y Checklist:

• All images have alt text (or alt="" for decorative)
• All form fields have labels
• Color is never the only indicator
• Focus visible on all interactive elements
• Keyboard navigation works throughout

Critical Success Factors:

• Automated testing catches 30-50% of issues
• Manual testing with real assistive tech required
• Include users with disabilities in testing </default_to_action>

Quick Reference Card

When to Use

• Legal compliance (ADA, Section 508, EU Directive)
• New feature development
• Before release validation
• Accessibility audits

WCAG 2.2 Levels

Level	Requirement	Target
A	Basic accessibility	Minimum legal
AA	Standard (most orgs)	Industry standard
AAA	Enhanced	Specialized sites

POUR Principles

Principle	Meaning	Key Tests
Perceivable	Can perceive content	Alt text, contrast, captions
Operable	Can operate UI	Keyboard, no seizures, navigation
Understandable	Can understand	Clear labels, predictable, errors
Robust	Works with assistive tech	Valid HTML, ARIA

Color Contrast Requirements

Content	AA Ratio	AAA Ratio
Normal text	4.5:1	7:1
Large text (18pt+)	3:1	4.5:1
UI components	3:1	-

---

Keyboard Navigation Testing

// Test all interactive elements reachable via keyboard
test('all interactive elements keyboard accessible', async ({ page }) => {
  await page.goto('/');

  const focusableElements = await page.$$('button, a, input, select, textarea, [tabindex]');

  for (const element of focusableElements) {
    await element.focus();
    const isFocused = await element.evaluate(el => document.activeElement === el);
    expect(isFocused).toBe(true);
  }
});

// Verify visible focus indicator
test('focus indicator visible', async ({ page }) => {
  await page.goto('/');
  await page.keyboard.press('Tab');

  const focusedElement = await page.locator(':focus');
  const outline = await focusedElement.evaluate(el =>
    getComputedStyle(el).outline
  );

  expect(outline).not.toBe('none');
});

---

Automated Testing with axe-core

Preferred: via the a11y-ally AQE skill (qe-browser + Vibium)

For new work, use the a11y-ally skill — it composes qe-browser (Vibium WebDriver BiDi) with axe-core, pa11y, and Lighthouse and produces a WCAG-tagged JSON report with remediation guidance. It avoids the 300MB Playwright install and is already wired into the AQE fleet.

# Runs axe-core + pa11y + Lighthouse via qe-browser (Vibium) engine
aqe skill run a11y-ally -- --url https://example.com --wcag AA

Fallback: Playwright + @axe-core/playwright

Keep this path when you have an existing Playwright suite and don't want to introduce a second browser runner, or when you need Firefox/Safari coverage that Vibium's Chrome-only BiDi backend can't provide today.

import { test, expect } from '@playwright/test';
import AxeBuilder from '@axe-core/playwright';

test('page has no accessibility violations', async ({ page }) => {
  await page.goto('/');

  const results = await new AxeBuilder({ page })
    .withTags(['wcag2a', 'wcag2aa', 'wcag22aa'])
    .analyze();

  expect(results.violations).toEqual([]);
});

// CI/CD integration
test('checkout flow accessible', async ({ page }) => {
  await page.goto('/checkout');

  const results = await new AxeBuilder({ page })
    .include('#checkout-form')
    .disableRules(['color-contrast']) // Fix in next sprint
    .analyze();

  expect(results.violations.filter(v =>
    v.impact === 'critical' || v.impact === 'serious'
  )).toHaveLength(0);
});

---

Screen Reader Testing Checklist

## VoiceOver (macOS) Testing
- [ ] Page title announced on load
- [ ] Headings hierarchy correct (h1 → h2 → h3)
- [ ] Landmarks present (nav, main, footer)
- [ ] Images have descriptive alt text
- [ ] Form labels read correctly
- [ ] Error messages announced
- [ ] Dynamic content updates announced (aria-live)

---

Agent-Driven Accessibility

// Comprehensive a11y validation
await Task("Accessibility Validation", {
  url: 'https://example.com/checkout',
  standard: 'WCAG2.2',
  level: 'AA',
  checks: ['keyboard', 'screen-reader', 'color-contrast'],
  includeScreenReaderSimulation: true
}, "qe-visual-tester");

// Fleet coordination for comprehensive testing
const a11yFleet = await FleetManager.coordinate({
  strategy: 'comprehensive-accessibility',
  agents: [
    'qe-visual-tester',     // Visual & keyboard checks
    'qe-test-generator',    // Generate a11y tests
    'qe-quality-gate'       // Enforce compliance
  ],
  topology: 'parallel'
});

---

Agent Coordination Hints

Memory Namespace

aqe/accessibility/
├── wcag-results/*       - WCAG audit results
├── screen-reader/*      - Screen reader test logs
├── remediation/*        - Fix recommendations
└── compliance/*         - Compliance reports

Fleet Coordination

const a11yFleet = await FleetManager.coordinate({
  strategy: 'accessibility-testing',
  agents: [
    'qe-visual-tester',   // axe-core, keyboard, focus
    'qe-test-generator',  // Generate a11y test cases
    'qe-quality-gate'     // Block non-compliant builds
  ],
  topology: 'parallel'
});

---

Related Skills

• visual-testing-advanced - Visual a11y checks
• mobile-testing - Mobile a11y (VoiceOver, TalkBack)
• compliance-testing - Legal compliance

---

Remember

1 billion people have disabilities. Inaccessible software excludes 15% of humanity. Legal requirements: ADA, Section 508, EU Directive 2016/2102. $13T purchasing power. 250%+ increase in lawsuits.

Automated testing catches only 30-50% of issues. Combine with manual keyboard testing, screen reader testing, and real user testing with people with disabilities.

With Agents: Agents automate WCAG 2.2 compliance checking, screen reader simulation, and focus management validation. Use agents to enforce accessibility standards in CI/CD and catch violations before production.