WCAG Structure

The WCAG official documentation is a bit overwhelming at first. It is structured in a way that makes it difficult to understand the big picture, and the language is technical. This section aims to provide an overview of the structure of the WCAG documentation, so you can better understand how to navigate it.

The current version of the criteria list is WCAG 2.2 (released in October 2023). WCAG 3.0 is currently in draft, but will not be released before several years.

Principles

Web accessibility is based on four core principles, often called the P.O.U.R. principles:

• Perceivable - Users must be able to perceive the web content, regardless of their sensory abilities (it can not be invisible to all of their senses)
• Operable - Interfaces must be operable, regardless of the user's physical abilities (they can not require an interaction that the user can not perform)
• Understandable - Users must be able to understand the content and the interface, regardless of their cognitive abilities (it can not be confusing)
• Robust - Websites must be compatible with assistive technologies and future-proofed for evolving tools and standards (it can not be fragile)

Guidelines

Under each principle, there is a list of guidelines that provide a more specific set of recommendations. There are 13 guidelines in total.

Criteria

Under each guideline, there is a list of success criteria that must be achieved in order to meet the guideline. There are 87 criteria in total, one of which is obsolete (but included for reference).

Conformance levels

Each criterion is assigned a level of conformance, which indicates how important it is to satisfy the criteria. There are three levels of conformance:

• A - High priority: Teams must satisfy these requirements, otherwise it will be impossible for large groups to access the web content
• AA - Medium priority: Teams must satisfy these requirements, otherwise some groups will find it difficult to access the web content
• AAA - Low priority: Teams may satisfy these requirements to make it easier for smaller groups to access the web content

You should aim for AA conformance, meaning you should satisfy all A and AA success criteria. You can also try to reach AAA conformance, but it is only required for specialized content (e.g. government websites or educational platforms).