What is WCAG?
WCAG (Web Content Accessibility Guidelines) is the international standard for web accessibility, published by the W3C, defining how to make web content perceivable, operable, understandable, and robust for people with disabilities.
How it works
WCAG is organized around four principles (POUR): Perceivable (information must be presentable in ways users can perceive), Operable (interface must be navigable by all users), Understandable (content and interface must be comprehensible), and Robust (content must work with current and future technologies). Each principle contains specific success criteria at three conformance levels: A (minimum), AA (standard target for most organizations and legal requirements), and AAA (highest). Key criteria include 4.5:1 color contrast for text, keyboard navigability for all functions, text alternatives for non-text content, and captions for video. WCAG 2.1 (current) added criteria for mobile and cognitive accessibility.
Applied example
A company audits their website against WCAG 2.1 AA and finds 147 violations: missing alt text on 80 images, 23 color contrast failures, 12 forms without proper labels, and 32 keyboard traps. Systematically fixing these issues not only achieves compliance but reduces support requests from all users by 15%.
Why it matters
WCAG provides the measurable, legally referenced standard that transforms web accessibility from a vague aspiration into a concrete, testable set of requirements.
