WCAG, the Web Content Accessibility Guidelines, can feel overwhelming. The current version (WCAG 2.2) has 13 guidelines and 86 success criteria across three conformance levels.

Most developers and designers never read them cover to cover. They don't need to. What they do need is a mental model, a way to think about accessibility that makes the specifics easier to understand and apply. That mental model is called POUR, the four foundational principles that every WCAG guideline sits underneath.

What POUR stands for
POUR is an acronym for the four principles that structure the entire WCAG standard:

• Perceivable: users can perceive the content (through sight, hearing, or touch)
• Operable: users can operate the interface (with keyboard, mouse, touch, or voice)
• Understandable: users can understand the content and how to use the interface
• Robust: the content works reliably across browsers, devices, and assistive technologies

Every WCAG guideline falls under one of these four principles. If your content fails on any one of them, a group of users is shut out, regardless of how well the other three are handled.

POUR has been the foundation of WCAG since version 2.0 was published in 2008. It carries through WCAG 2.1, WCAG 2.2, and will continue into WCAG 3.0 (currently in development). Learning POUR is learning the language of accessibility.

Full article covering each principle, with code snippets and practical tips.