What is WCAG?
WCAG, or Web Content Accessibility Guidelines, is the international technical standard for web accessibility, published and maintained by the World Wide Web Consortium. It defines the requirements that websites and digital products must meet to be perceivable, operable, understandable, and robust for users with disabilities. WCAG is organized around four principles, abbreviated as POUR: Perceivable means information must be presentable to users in ways they can perceive. Operable means interface components must be navigable. Understandable means information and operation must be understandable. Robust means content must be interpretable by a wide variety of assistive technologies.
What are the WCAG conformance levels?
WCAG defines three conformance levels. Level A covers the most basic requirements: failing to meet Level A makes the product inaccessible to many users with disabilities. Level AA is the standard required by most accessibility laws and regulations globally, including the European Accessibility Act, the ADA in the United States, and EN 301 549. It includes Level A requirements plus additional criteria covering color contrast, keyboard navigation, captions, and more. Level AAA covers enhanced requirements that are not achievable for all content types and are not generally required by law, but represent best practice for products with specific accessibility goals.
How does WCAG apply to UX design practice?
WCAG translates into specific design requirements that affect every stage of the design process. During visual design, color contrast ratios must be verified, focus states must be designed rather than removed, and information must not be conveyed through color alone. During interaction design, all functionality must be keyboard accessible, time limits must have extensions or disabling options, and content that moves or flashes must meet strict criteria. During content design, language must be clear, error messages must be descriptive, and labels must be present and correct. Integrating WCAG requirements into the design process from the start is significantly cheaper than retrofitting accessibility after development is complete.