WCAG

WCAG (Web Content Accessibility Guidelines) is an international set of guidelines specifying how to create web content accessible to the widest possible audience, including people with visual, hearing, motor and cognitive disabilities. The guidelines are developed by the W3C consortium and form the basis of many legal regulations concerning digital accessibility.

The four principles of WCAG

WCAG rests on four principles, captured by the acronym POUR: content must be perceivable — for example images described with an alt attribute and videos with captions; operable — usable with a keyboard alone; understandable — with clear language and predictable behaviour; and robust — correctly interpreted by different browsers and assistive technologies such as screen readers.

Conformance levels and importance

WCAG defines three levels of conformance: A (minimum), AA (the standard required by most regulations) and AAA (the highest, hard to meet in full). In practice, the target for most sites is level AA, which EU regulations, among others, require. Applying WCAG is not only a matter of legal compliance — an accessible site is more convenient for all users, improves UX and often goes hand in hand with better SEO and a more thoughtful UI. Accessibility is best designed in from the start, because retrofitting a finished site is far more expensive than accounting for the guidelines at the design stage. Treating conformance as an ongoing process, supported by regular testing with users and automated tools, helps keep a site accessible despite continual change.