Web Content Accessibility Guidelines (WCAG)

The WCAG are an international standard for the accessible design of all information on a website or web application, including text, images, forms, audio and video. The guidelines were developed by the World Wide Web Consortium (W3C).

The WCAG are based on four core principles designed to ensure that web content is perceivable, operable, understandable and robust.

1. Perceivability: Information and user interfaces must be presented to users in such a way that they can perceive them (e.g. through text alternatives for non-text content, subtitles for videos, sufficient contrast).
2. Operability: Elements of the user interface and navigation must be operable (e.g. keyboard accessibility, sufficient time for operation, avoidance of flickering content).
3. Comprehensibility: Information and the operation of the user interface must be comprehensible (e.g. legible and understandable text, predictable navigation, error messages).
4. Robust: Content must be robust enough to be reliably interpreted by a wide range of user agents (web browsers, assistive technologies) and remain compatible with future technologies.