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WCAG success criteria, explained for testing

One page per requirement: the official wording, the matching EN 301 549 clauses, what it means on web, iOS, and Android, and what actually counts as a fail.

Looking for the strategic overview that used to live here? Read the executive guide to WCAG.

All 55 Level A and AA success criteria, each explained in depth

Principle 1

Perceivable

Users can perceive the content: alternatives, contrast, adaptable structure.

20 criteria

Principle 2

Operable

Users can operate the interface: keyboard, timing, navigation, input.

20 criteria

Principle 3

Understandable

Users can understand content and controls: language, predictability, input help.

13 criteria

Principle 4

Robust

Content works reliably with assistive technologies.

2 criteria

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