Web accessibility standards and principles

  • 4 minutes

Internationally recognized, the industry standard for web accessibility is the Web Content Accessibility Guidelines (WCAG). This standard explains how to make web content more accessible to people with disabilities and is organized into four principles: Perceivable, Operable, Understandable, and Robust.

Each principle has several guidelines, with a varying number of success criteria. The WCAG success criteria are further divided into three levels of conformance: A, AA, and AAA, indicating a degree of accessibility and compliance.

How does WCAG relate to other accessibility laws and standards?

Different countries and regions have their own laws and regulations. Many may reference or incorporate WCAG principles, while also including their own specific requirements and exceptions.

Let's look at three examples of other standards or laws that incorporate the Web Content Accessibility Guidelines (WCAG):

  • EN 301 549 is a European standard for the accessibility of information and communication technologies like websites, software, and hardware. It sets public procurement requirements in Europe and has been adopted as a procurement standard in many non-European countries. EN 301 549 is also expected to set the compliance bar for the European Accessibility Act (EAA), a law that sets accessibility requirements for many products and services offered in the European Union as of June 28, 2025. The current version of EN 301 549 incorporates WCAG 2.1 level AA.

  • Section 508 of the Rehabilitation Act is a law in the United States that requires federal agencies to ensure their electronic and information technology is accessible to people with disabilities. A federal agency called the United States Access Board creates specific regulations explaining what Section 508 requires. Those regulations incorporate WCAG 2.0 level AA as the standard for web accessibility.

  • The EU Web Accessibility Directive requires public sector websites and mobile applications in the European Union to be accessible to people with disabilities. It requires compliance with WCAG 2.1 level AA.