WCAG (Web Content Accessibility Guidelines) are international technical standards developed by the W3C to make digital content accessible to people with disabilities. Built on four principles (Perceivable, Operable, Understandable, Robust) and three conformance levels (A, AA, AAA), WCAG 2.2 is the current standard referenced by accessibility laws worldwide, including the ADA and Section 508.
WCAG (Web Content Accessibility Guidelines)
Key facts about WCAG
- Full name: Web Content Accessibility Guidelines
- Developed by: World Wide Web Consortium (W3C)
- Purpose: Make web content accessible to people with disabilities
- Core framework: Four principles known as POUR: Perceivable, Operable, Understandable, Robust
- Conformance levels: A (minimum), AA (standard), AAA (highest)
- Current version: WCAG 2.2, published October 2023
- Legal relevance: Referenced by the ADA, Section 508, EN 301 549, and other accessibility laws
What is WCAG?
WCAG stands for Web Content Accessibility Guidelines. They are a set of internationally recognized technical standards developed by the W3C Web Accessibility Initiative (WAI) to ensure websites and digital content are usable by people with disabilities.
WCAG applies to a broad range of disabilities, including visual, auditory, physical, cognitive, and neurological conditions. The guidelines are structured around four principles, testable success criteria, and three conformance levels.
The four WCAG principles (POUR)
Principle | What it requires |
|---|---|
Perceivable | Content must be presentable in ways users can perceive, such as text alternatives for images and captions for video |
Operable | Interfaces must be navigable via keyboard, with sufficient time to interact |
Understandable | Content and navigation must be clear, readable, and predictable |
Robust | Content must work across different browsers, devices, and assistive technologies |
WCAG conformance levels
- Level A: The minimum level of accessibility. Covers the most critical barriers.
- Level AA: The standard required by most laws and regulations, including the ADA and Section 508. Addresses the most common barriers for users with disabilities.
- Level AAA: The highest level of accessibility. Not required as a general target for entire websites due to the complexity of implementation.
Most organizations and legal frameworks target Level AA compliance.
Here's only the updated WCAG versions section to replace the existing one in the WCAG glossary page:
WCAG versions
- WCAG 2.0 (2008): Established the foundational POUR framework and success criteria.
- WCAG 2.1 (2018): Added 17 criteria addressing mobile accessibility, low vision, and cognitive disabilities.
- WCAG 2.2 (2023): Added 9 further criteria focused on cognitive and learning disabilities and mobile users.
- WCAG 3.0 (in development): A next-generation framework currently under development by the W3C. It proposes a broader scope covering websites, mobile apps, software, and emerging technologies, and introduces an outcome-based scoring model to replace the current pass/fail approach. No final release date has been announced.
Each version of WCAG 2.x is backward compatible. WCAG 3.0 represents a more significant structural change and is not yet referenced by accessibility regulations. Organizations should currently focus on WCAG 2.1 or 2.2 Level AA for legal compliance.
WCAG and legal compliance
WCAG is not a law, but it is the technical benchmark referenced by accessibility legislation in many countries, including the ADA in the United States, Section 508 for federal agencies, and the European Accessibility Act (EAA). Non-compliance can expose organizations to legal risk and complaints.
WCAG and digital accessibility solutions
Organizations implement WCAG as part of broader accessibility programs. Dedicated tools and platforms can help organizations:
- Identify and remediate accessibility issues through accessibility testing and audits
- Support users with disabilities via an accessibility widget
- Publish and maintain an accessibility statement
- Manage accessibility issue reporting
For more information on how Clym supports WCAG compliance, see our accessibility solutions.
Related compliance terms
Commonly asked questions
WCAG stands for Web Content Accessibility Guidelines. They are international standards developed by the W3C to make digital content accessible to people with disabilities.
The four principles are Perceivable, Operable, Understandable, and Robust, collectively known as POUR. Each principle contains guidelines and testable success criteria.
Level A is the minimum standard. Level AA addresses the most common accessibility barriers and is the level required by most laws. Level AAA is the highest standard and is not generally required for entire websites.
WCAG itself is not a law, but it is referenced by accessibility legislation in many jurisdictions. Meeting Level AA is effectively required for legal compliance in many countries.
WCAG 2.2, published in October 2023, is the current version. It builds on WCAG 2.1 with additional criteria for cognitive, learning, and mobile accessibility.
Yes. While WCAG was originally developed for websites, its principles and success criteria apply to mobile applications as well.
Adam is the Head of Digital Marketing at Clym, where he leverages his diverse expertise in marketing to support businesses with their compliance needs and drive awareness about data privacy and web accessibility. As one of the company’s original team members, Adam has been instrumental in shaping its journey from the very beginning. When he’s not diving into marketing strategies, Adam can be found cheering on his favorite sports teams or enjoying fishing.
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