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The four WCAG principles

WCAG places all success criteria under four principles. A good overview before going into the individual criteria.

Perceivable

Content for all senses: text alternatives for images, sufficient contrast, structure independent of the visual rendering, captions for video.

Operable

Everything with the keyboard, enough time, no seizure triggers, clear navigation, meaningful link texts, visible focus.

Understandable

Specify the language, predictable behaviour, help on input errors, consistent operation.

Robust

Valid, semantic HTML, so that assistive technologies work reliably — today and in the future.

How a11yglass helps

The free scan checks the delivered HTML and CSS for automatically recognisable WCAG breaches, and names per finding the success criterion and a concrete step. It finds roughly 20–35% of issues and does not replace a full assessment.

Read on

• Colour contrast per WCAG 1.4.3
• Keyboard operation per WCAG 2.1.1
• The EAA for websites

General information to the best of our knowledge, not legal advice. For an individual case, contact a law firm specialising in IT law.