WCAG 2 Overview

Introduction

Web Content Accessibility Guidelines (WCAG) 2 is developed through the W3C process in cooperation with individuals and organizations around the world, with a goal of providing a single shared standard for web content accessibility that meets the needs of individuals, organizations, and governments internationally.

The WCAG documents explain how to make web content more accessible to people with disabilities. Web “content” generally refers to the information in a web page or web application, including:

Who WCAG is for

WCAG is for those who want a technical standard. It is not an introduction to accessibility. For links to introductory material, see “Where should I start?” in the FAQ.

WCAG is primarily intended for:

To meet the needs of others — including policy makers, managers, and researchers — there are many different WAI Resources.

What is in WCAG 2

The WCAG 2.2 has 13 guidelines. The guidelines are organized under 4 principles: perceivable, operable, understandable, and robust.

For each guideline, there are testable success criteria. The success criteria are at three levels: A, AA, and AAA.

The success criteria are what determine “conformance” to WCAG. That is, in order to meet WCAG, the content needs to meet the success criteria. Details are in the Conformance section of WCAG.

For a short summary of the WCAG 2 guidelines, see WCAG 2 at a Glance.

Supporting material and supplemental guidance

The following resources help you understand and implement WCAG, and improve accessibility beyond WCAG:

Please read about these WCAG 2 resources from WCAG 2 Documents.

WCAG 2.0, 2.1, 2.2

The Web Content Accessibility Guidelines (WCAG) standards are referenceable when they are published as a ‘W3C Recommendation’ web standard.

For information on the updates, see the WCAG 2 FAQ.

WCAG 2.0, 2.1, and 2.2 are designed to be “backwards compatible”, which means content that conforms to WCAG 2.2 also conforms to WCAG 2.1 and WCAG 2.0. If you want to meet all the versions, you can use the WCAG 2.2 resources and you don’t need to bother looking at earlier versions.

All the success criteria from 2.0 are included in 2.1, and all from 2.1 are in 2.2 (except 4.1.1, explained in the next paragraph).

A few things have changed, and we intend the updates in the related documents to support backwards compatibility in practice. The main change is that in WCAG 2.2, one success criteria (4.1.1 Parsing) is obsolete. Notes added to WCAG 2.1 and WCAG 2.0 errata address this, as explained in WCAG 2 FAQ, 4.1.1 Parsing. WCAG 2.2 also includes Notes about different languages; more information is in WCAG 2 FAQ, internationalization.

WCAG 2.0, WCAG 2.1, and WCAG 2.2 are all existing standards. WCAG 2.2 does not deprecate or supersede WCAG 2.1, and WCAG 2.1 does not deprecate or supersede WCAG 2.0. W3C encourages you to use the latest version of WCAG.

Translations

Authorized Translations and unofficial translations of WCAG 2 are listed in WCAG 2 Translations.

ISO/IEC 40500, EAA, EN 301 549

WCAG 2.2 is an approved International Organization for Standardization (ISO) standard: ISO/IEC 40500:2025, and is available free from ISO. ISO/IEC 40500:2025 is exactly the same as the October 2023 version of WCAG 2.2. We expect the December 2024 version of WCAG 2.2 to be available as ISO/IEC 40500:2026 by late 2026.

In addressing the European Accessibility Act (EAA), most organizations use WCAG and the European Standard EN 301 549: Accessibility requirements for ICT products and services. EN 301 549 currently uses WCAG 2.1. We expect the next version of EN 301 549 to use the latest version of WCAG 2.2.

To find how laws around the world use WCAG, see Web Accessibility Laws & Policies.

W3C encourages you to use the latest version of WCAG. Content that meets WCAG 2.2 also meets WCAG 2.1 and WCAG 2.0.

Who develops WCAG

The WCAG technical documents are developed by the Accessibility Guidelines Working Group (AG WG) (formerly the Web Content Accessibility Guidelines Working Group), which is part of the World Wide Web Consortium (W3C) Web Accessibility Initiative (WAI).

WAI updates Techniques for WCAG 2 and Understanding WCAG 2 periodically. We welcome comments and submission of new techniques.

Opportunities for contributing to WCAG and other WAI work are introduced in Participating in WAI.

More about WCAG

WCAG is part of a series of accessibility guidelines, including the Authoring Tool Accessibility Guidelines (ATAG) and the User Agent Accessibility Guidelines (UAAG). Essential Components of Web Accessibility explains the relationship between the different guidelines.

Frequently asked questions (FAQ)

See the WCAG 2 FAQ for more information on:

JSON machine-readable files

The WCAG JSON (JavaScript Object Notation) files include the principles, guidelines, success criteria, and glossary terms from WCAG and the supporting Techniques. For more information, see JSON Serialization of WCAG 2 – GitHub .

WCAG 3

For information on the early draft of W3C Accessibility Guidelines 3.0 (formerly known as “Silver”), see the WCAG 3 Introduction.

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