The Web Content Accessibility Guidelines (WCAG) are the international guidelines for making websites and apps accessible. Created by the W3C Web Accessibility Initiative (WAI), it gives designers and developers a shared checklist for accessibility best practices.
WCAG uses three levels of compliance:
- Level A (Essential): The basic foundation. Without this, many users cannot access your content.
- Level AA (Standard): The most common goal for professional websites. It balances practical effort with equal access.
- Level AAA (Exceptional): The gold standard. Achieving this means your site is accessible to almost everyone, but it’s not always realistic for every project.
To meet these standards, WCAG organizes its specific rules under four guiding principles: Perceivable, Operable, Understandable, and Robust. Known as the POUR principles, they provide the functional framework for building truly accessible digital experiences.