WCAG 2.1 Section 5.2.1: Conformance Level
Estimated read time: 4–5 minutes
What Is Conformance Level?
Section 5.2.1 of WCAG 2.1 defines the three levels of accessibility conformance: Level A, Level AA, and Level AAA. Each level builds on the previous one, with more requirements for higher levels.
- Level A (Minimum): The web page satisfies all Level A success criteria, or provides a conforming alternate version.
- Level AA: The web page satisfies all Level A and Level AA success criteria, or provides a Level AA conforming alternate version.
- Level AAA: The web page satisfies all Level A, Level AA, and Level AAA success criteria, or provides a Level AAA conforming alternate version.
A conforming alternate version is a version of the content that meets the required level and provides all the same information and functionality.
How Do the Levels Work?
- Level A is the most basic level of accessibility. It addresses the most critical barriers for users with disabilities.
- Level AA includes all Level A requirements plus additional criteria that address a wider range of barriers. Most organizations aim for Level AA.
- Level AAA is the highest level, with the most comprehensive set of requirements. It is not always possible or practical to meet all AAA criteria for all content.
Note: Although conformance can only be achieved at the stated levels, authors are encouraged to report any progress toward meeting success criteria from all levels beyond the achieved level.
Note: It is not recommended that Level AAA conformance be required as a general policy for entire sites, because it is not possible to satisfy all Level AAA success criteria for some content.
Why Does This Matter?
Understanding conformance levels helps organizations:
- Set realistic accessibility goals
- Make accurate conformance claims
- Improve accessibility for all users
References & Further Reading
- WCAG 2.1 Section 5.2.1: Conformance Level
- WCAG 2.1 Full Specification
- Understanding Conformance Requirements
Conformance levels help you measure and communicate your progress toward true web accessibility.