Conformance Levels
The Web Content Accessibility Guidelines (WCAG) are organized into three distinct levels of conformance. Most organizations targetLevel AAas the standard for legal compliance and best practices.
Level A
Essential accessibility features. Without these, many disabled users cannot use the site at all.
- Keyboard navigation
- Alt text for images
- Captions for video
Level AA
The global standard for accessibility (ADA, Section 508, GDPR). Addresses common barriers.
- Color contrast (4.5:1)
- Responsive text resizing
- Consistent navigation
Level AAA
The highest standard, intended for specialized content. Often not possible for all types of content.
- Sign language interpretation
- Strict contrast (7:1)
- No strict time limits
The POUR Principles
WCAG is organized around four foundational principles known as POUR. If your content violates any of these, users with disabilities cannot access it.
Perceivable
Information must be presented in ways users can perceive (sight, hearing, touch).
Operable
User interface components and navigation must be operable via keyboard or voice.
Understandable
Information and operation of the user interface must be clear and consistent.
Robust
Content must be robust enough to be interpreted reliably by assistive technologies.
Why it matters
- 1 in 4 adults in the US have some type of disability.
- Accessibility lawsuits have increased by 200% over the last 5 years.
- Accessible sites rank better in SEO and reach a wider audience.
- Inclusive design improves usability for all users, including mobile.
Official Standards
Access the full technical specifications directly from the W3C. These documents are comprehensive and serve as the definitive source for compliance.