WCAG

The Web Content Accessibility Guidelines (WCAG) are part of a series of web accessibility guidelines published by the Web Accessibility Initiative (WAI) of the World Wide Web Consortium (W3C), the main international standards organization for the Internet. They are a set of guidelines that specify how to make content accessible, primarily for people with disabilities—but also for all user agents, including highly limited devices, such as mobile phones. The current version, WCAG 2.0, was published in December 2008 and became an ISO standard, ISO/IEC 40500:2012 in October 2012.

The first web accessibility guideline was compiled by Gregg Vanderheiden and released in January 1995, just after the 1994 Second International Conference on the World-Wide Web (WWW II) in Chicago (where Tim Berners-Lee first mentioned disability access in a keynote speech after seeing a pre-conference workshop on accessibility led by Mike Paciello).

Over 38 different Web access guidelines followed from various authors and organizations over the next few years. These were brought together in the Unified Web Site Accessibility Guidelines compiled at the University of Wisconsin-Madison. Version 8 of the Unified Web Site Accessibility Guidelines, published in 1998, served as the starting point for the W3C's WCAG 1.0.

The WCAG 1.0 was published and became a W3C recommendation on 5 May 1999. They have since been superseded by WCAG 2.0.

WCAG 1.0 consist of 14 guidelines—each of which describes a general principle of accessible design. Each guideline covers a basic theme of web accessibility and is associated with one or more checkpoints that describes how to apply that guideline to particular webpage features.

Each of the in total 65 WCAG 1.0 checkpoints has an assigned priority level based on the checkpoint's impact on accessibility:

In February 2008, The WCAG Samurai, a group of developers independent of the W3C, and led by Joe Clark, published corrections for, and extensions to, the WCAG 1.0.

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