WCAG Guidelines

Woo-CAG? WIC-AG? Wuh-CAG? Double-yew Cee A Gee? The Web Content Accessibility Guidelines (Opens in new window) (WCAG) are a key component of Web Accessibility, but they aren't always easy to understand or talk about.

The WCAG Guidelines are technical standards developed, maintained, and updated by the World Wide Web Consortium (W3C). The current edition of WCAG is 2.2, but it's common for some groups to still use 2.1 or 2.0. 2.2 adds several additional criteria to those in 2.0. and 2.1 These guidelines can be difficult to read and implement for lay users because they are aimed at web developers and folks with technical expertise. The Guidelines also don't tell you what to do, they tell you what your product must accomplish. There is more than one way to satisfy the guidelines.

The WCAG guidelines are important because compliance with the guidelines is referenced in several legal standards, including Section 508, the Accessibility for Ontarians with Disabilities Act, and the European standard EN 301 549.

The Four WCAG Principles

The WCAG guidelines are organized under four different principles. These are often called POUR. Each principle has several defined and numbered criteria. Each criteria has a page that defines the intent, benefits, examples and techniques to satisfy the criteria.

Perceivable

This principle requires that your content can be perceived. Because all users do not have the same abilities, effectively this principle is about providing options for how information is read/viewed or understood. This principle includes criteria for captions (1.2.2 prerecorded and 1.2.4 live), audio description (1.2.3), use of color (1.4.1) and more.

Operable

This principle requires that users can navigate and operate your website or other content. This principle includes criteria for keyboard navigation (2.1), flexible timing (2.2), descriptive link text (2.4.4 and 2.4.9), focus order (2.4.3) and more.

Understandable

This principle requires that users can understand what they can perceive and operate. This principle includes criteria for a declared language (3.1.1 and 3.1.2), reading level (3.1.5), consistent navigation (3.2.3), error identification (3.3.1) and more.

Robust

This principle requires websites to be interoperable with as many soft and hardwares as possible, including assistive technology. This principle includes criteria for  compatibility (4.1), parsing (4.1.1), names, roles and values (4.1.2), and status messages (4.1.3).

Levels of Conformance

Each WCAG criteria is labeled A, AA, or AAA.

  • A is the lowest conformance. Consider this almost accessible.
  • AA is the mid-range conformance level. This is the level specified by current legal standards.
  • AAA is the highest level of conformance and includes criteria that aren't as easy to satisfy.

The conformance levels stack. When someone says their website meets WCAG AA criteria, this means the website meets all A and AA criteria.

WCAG and this Guide

This guide and related materials (the Accessibility Topics / FAQ (Opens in new window) and Instructional Content Accessibility Tool (Opens in new window)) do not include all WCAG criteria. WCAG is a guideline for web designers and creators. These folks create textual or video content like we do, but they also do more technical coding and website building that we do not. These more technical oriented criteria are omitted in this material. Additionally, this material includes some best practices that are not included in the WCAG standards.