WCAG

The Web Content Accessibility Guidelines (WCAG) are a comprehensive technical standard from the W3C describing what it means for a web page to be accessible to people with disabilities — visual, motor, cognitive, auditory. The guidelines are structured around four principles: content must be Perceivable, Operable, Understandable, and Robust.

WCAG defines three conformance levels: A (the minimum), AA (the practical bar most jurisdictions and clients require), and AAA (aspirational, rarely fully achievable). AA covers contrast ratios (4.5:1 for body text), keyboard navigability, focus visibility, alternative text on images, accessible names on interactive elements, and a long list of similar concrete requirements.

In many countries, AA conformance is a legal obligation for public-sector and large commercial sites. Even where it isn’t, hitting AA tends to ship a site that simply works better for everyone — older users on lower-contrast monitors, anyone using a phone in sunlight, voice-control users, and so on.