Lesson 2 / 26
WCAG standards
Learn WCAG levels A, AA and AAA and the four POUR principles that define accessible web content.
WCAG versions & levels
WCAG 2.2 is the current W3C recommendation (2.1 and 2.0 are earlier versions; 3.0 is in draft). Three levels: A (basic), AA (enhanced; the legal baseline in most regions), AAA (optimal). The guidelines follow four principles: Perceivable, Operable, Understandable, Robust (POUR).
POUR principles
Perceivable: users can see/hear content (color + text, captions). Operable: keyboard, voice, switch—no mouse-only interactions. Understandable: clear language, predictable design, error recovery. Robust: works with assistive tech (screen readers, voice control, etc.).
Practical compliance
Most organizations target WCAG 2.2 AA (or 2.1 AA where a law names it). This requires 4.5:1 text contrast, keyboard navigation, alt text, properly labelled forms and ARIA where needed. AAA is ideal but not always required.
Where to learn more
Visit w3.org/WAI/WCAG22 for the specification and webaim.org for articles and checklists.
Compliance audit
Third-party audits provide formal compliance assessment. Useful for legal proof and improvement recommendations.