Software Testing - Accessibility Testing (WCAG Compliance)

Accessibility Testing verifies that software can be used by people with disabilities, ensuring compliance with WCAG (Web Content Accessibility Guidelines).
It focuses on users with visual, auditory, motor, and cognitive impairments.

Accessibility is not optional — it is a quality and compliance requirement.

What Is WCAG?

WCAG is an international standard published by the World Wide Web Consortium (W3C) that defines how to make digital content accessible.

WCAG Principles (POUR)

  1. Perceivable – content can be perceived (text alternatives, captions)

  2. Operable – interface can be used via keyboard and assistive tech

  3. Understandable – content and navigation are predictable

  4. Robust – compatible with assistive technologies

Types of Disabilities Covered

  • Visual: blindness, low vision, color blindness

  • Auditory: partial or total hearing loss

  • Motor: limited hand movement, tremors

  • Cognitive: dyslexia, memory issues, ADHD

Key Accessibility Testing Areas

1. Keyboard Accessibility

  • All functionality must be usable without a mouse

  • Logical tab order

  • Visible focus indicators

2. Screen Reader Compatibility

  • Proper use of HTML semantics

  • ARIA roles and labels

  • Meaningful page structure (headings, landmarks)

3. Color Contrast and Visual Design

  • Text contrast meets WCAG ratios

  • No color-only instructions

  • Scalable text without layout breakage

4. Forms and Error Handling

  • Labels linked to inputs

  • Clear error messages

  • Accessible validation feedback

5. Multimedia Accessibility

  • Captions for videos

  • Transcripts for audio

  • Controls accessible via keyboard

Levels of WCAG Compliance

Level Meaning
A Basic accessibility
AA Industry standard (most required)
AAA Highest level (not always practical)

Most organizations target WCAG 2.1 AA.

Accessibility Testing Methods

Automated Testing

  • Catches common issues (missing labels, contrast errors)

  • Fast but limited

Manual Testing

  • Keyboard-only navigation

  • Screen reader testing

  • Essential for real usability

Assistive Technology Testing

  • Screen readers

  • Voice control

  • Switch devices

Common Accessibility Tools

  • Axe

  • Lighthouse

  • WAVE

  • NVDA / JAWS (screen readers)

Accessibility in CI/CD

  • Automated accessibility checks in pipelines

  • Fail builds for critical violations

  • Prevent regressions early

Why Accessibility Testing Matters

  • Legal compliance

  • Better user experience

  • Wider audience reach

  • Ethical responsibility

  • Higher product quality

Limitations

  • Automation cannot catch all issues

  • Requires human judgment

  • Needs ongoing maintenance