Explanation of WCAG

Published:: 2023-07-10
Updated:: 2023-11-23

The Web Content Accessibility Guidelines (WCAG) are a set of guidelines and standards that ensure that web content is accessible to people with disabilities. These guidelines are based on four principles: perceivable, operable, understandable, and robust, and are organized into three levels of conformance: A, AA, and AAA. They are widely adopted as the international standard for evaluating the accessibility of web content and play a crucial role in making web accessible to all users.

Web Content Accessibility Guidelines (WCAG) #

The Web Content Accessibility Guidelines (WCAG) are a set of guidelines and standards created by the World Wide Web Consortium (W3C) to ensure that web content is accessible to people with disabilities.

The W3C employs a consensus-based process to draft web standards, wherein stakeholders, including industry experts, developers, and users, engage in open discussions and collaborative decision-making. Through this inclusive approach, the W3C ensures that web standards reflect the collective expertise and requirements of the web community, leading to widely accepted and interoperable standards.

Principles #

The Web Content Accessibility Guidelines are based on four principles: perceivable, operable, understandable, and robust.

Perceivable #

Perceivable refers to the ability for users to perceive the content through various means, such as text alternatives for non-text content and captions for audio content. This principle also includes the ability for users to adjust the content’s presentation, such as through resizing text or adjusting the color contrast.

Operable #

Operable refers to the ability for users to interact with the content, including through keyboard-only navigation and providing multiple ways to access content. This principle also includes the ability for users to pause, stop, or hide content that may cause seizures or other physical reactions.

Understandable #

Understandable refers to the ability for users to understand the content, including through clear and simple language and providing context for content that may be ambiguous. This principle also includes the ability for users to correct errors and the ability to navigate and find content easily.

Robust #

Robust refers to the ability for the content to be interpreted by a wide variety of user agents (e.g. Browsers, Web crawlers, assistive technologies, etc.) and to work on a wide variety of devices and platforms.

Levels of conformance #

WCAG guidelines are organized into three levels of conformance: A, AA, and AAA.

Level A is the most basic level, and includes guidelines that ensure the content is accessible to the widest range of users, including those with disabilities.

Level AA includes additional guidelines that provide a greater level of accessibility, and Level AAA includes the most stringent guidelines for accessibility.

Technology and platform agnostic #

WCAG guidelines are not specific to any particular technology or platform, and can be applied to a wide range of web content, including web pages, multimedia, and software applications.

Conclusion #

The Web Content Accessibility Guidelines provide a set of objective criteria to evaluate the accessibility of web content.

The guidelines are developed through a consensus-based process involving experts in accessibility, web development, and user experience. They are widely adopted and an international ISO standard (ISO/IEC 40500:2012) for evaluating the accessibility of web content and they are an important reference for web developers, designers and evaluators when creating accessible web content.