The Web Content Accessibility Guidelines [WCAG] form the core of Web Accessibility Initiative [WAI] of the World Wide Web Consortium (W3C), the main standardization board for Internet activities.
Despite the web-centric name, the organization’s efforts span native digital solutions (such as Apple’s [Apple-accessibility] and Microsoft’s offerings [Microsoft-accessibility] as well as Google’s Android [Android-accessibility]) alongside those utilised in pure web browser context.
While the foundation of the organization is ewefnsuring access to people with disabilities, the majority of the requirements benefit all end users, providing methods and tools to guarantee that the content is visible and interactable on the massive variety of devices and services.
The current version of WCAG is 2.1. New versions will require non-trivial changes to user interfaces, and compliance cannot be taken for granted.
The WCAG consists of twelve guidelines organised under four principles, with each guideline containing individual success criteria. There are three levels of conformance that correspond to an increasing number of success criteria required: A (the service must satisfy this criterion), AA (… should …) and AAA (… may …).
The WCAG is used as a law in the European Union and multiple other countries. In the context of the European Union, EU Directive 2016/2102 requires websites and mobile applications of public sector entities to conform to WCAG 2.1 Level AA. The standard version in the legislation has been updated once and will be as new versions are released.
The four principles, defining that a service must be – perceivable, operable, understandable, and robust – provide the framework in which the elements of the user experience are considered.
Taken as a whole, the principles state that each end user, no matter if they have disabilities or other factors, shall be treated uniformly and equally.
As expected for a globally required and non-trivial compliance, the specifications are complemented with documentation, tools that measure accessibility (e.g., Lighthouse), and frameworks that assist in fulfilling the requirements (e.g. react-aria).
Accessibility is a general concern, but to comply with the requirements, each component of the skills data space that provides a user interface must take the requirements into account and be implemented accordingly.
