Web Content Accessibility Guidelines (WCAG) is the benchmark for crafting web-based content (like websites and web-based applications) that can be accessed by users of all abilities, especially those relying on assistive technologies. These guidelines, set by the Web Accessibility Initiative of the World Wide Web Consortium (W3C), form the global standard for web accessibility.
WCAG’s accessibility standards are based on four principles (often referred to as POUR):
- Perceivable: Information and user interface components must be presented to users in ways that they can perceive. For example, it’s important to present information that can be perceived in different ways, where a user can adjust color contrast or font size, or view captions for videos.
- Operable: User interface components and navigation must be functional for users in ways they can operate. For example, a user must be able to perform required interactions using a keyboard or voice commands, not just using a mouse.
- Understandable: Information and user interface operation must be understandable. For example, information and instructions should be clear and navigation methods should be easy to understand and use.
- Robust: Content must be robust enough so that it can be interpreted reliably by a wide variety of users and types of assistive technologies. As technologies evolve, code and content should remain accessible for users of common and current assistive devices and tools.
From WCAG 2.0’s inception in 2008 to the release of WCAG 2.2 in October 2023, each update builds upon its predecessor, maintaining backward compatibility while adding additional standards. For example, WCAG 2.1 added success criteria to 2.0 to improve mobile (and other small screen) experiences, and enhancements for people with low vision, motor and dexterity disabilities, and cognitive disabilities. WCAG 2.2 added more success criteria to elevate these standards. By conforming to the latest WCAG version, like WCAG 2.2, your experience automatically conforms with previous versions, 2.1 and 2.0.