WCAG Compliance: The Complete Guide to Conformance in 2026

What WCAG actually is

The Web Content Accessibility Guidelines (WCAG) are a set of technical standards published by the World Wide Web Consortium (W3C) through its Web Accessibility Initiative (WAI). They define how to make digital content — websites, apps, PDFs, multimedia — usable by people with disabilities.

WCAG is not a law. It is a technical specification. But it has become the global reference point for digital accessibility legislation. When a law says “accessible,” it almost always means WCAG compliant at Level AA.

The four POUR principles

All WCAG success criteria are organized under four high-level principles, collectively known as POUR. Every criterion under WCAG is assigned to one of these four:

• Perceivable: Information and UI components must be presentable in ways users can perceive. Nothing invisible to all senses. Examples: alt text for images, captions for video, sufficient color contrast.
• Operable: All functionality must be operable by a keyboard, not just a mouse. Nothing that traps keyboard focus. No time limits that cannot be extended.
• Understandable: Content and UI behavior must be understandable. Consistent navigation, clear error messages, readable language.
• Robust: Content must be robust enough for current and future assistive technologies to interpret it. Clean, valid, semantic HTML.

Conformance levels A, AA, AAA

Each WCAG success criterion is assigned a conformance level: A, AA, or AAA.

• Level A: The minimum. Failing these criteria makes content inaccessible to most assistive technology users. 30 criteria in WCAG 2.2.
• Level AA: The practical and legal standard. Builds on Level A. Addresses the most common real-world barriers. 20 additional criteria in WCAG 2.2.
• Level AAA: The highest level. Aspirational, not required by any law. Some criteria are impossible for all content types to meet simultaneously.

When any law, policy, or procurement requirement says “WCAG compliant,” it means Level A + Level AA together. You cannot skip Level A and only do AA.

WCAG versions explained

WCAG versions are backward compatible. Meeting WCAG 2.2 AA means you also meet 2.1 AA and 2.0 AA.

Which laws require WCAG

Common WCAG violations

These are the failures that appear on virtually every automated audit and drive most accessibility lawsuits:

• Missing or inadequate alt text on images
• Insufficient color contrast (below 4.5:1 for normal text)
• Interactive elements not reachable by keyboard
• Form inputs without associated labels
• Audio or video with autoplay and no pause control
• Videos without captions
• Links with non-descriptive text such as “click here” or “read more”
• No skip navigation link for keyboard users
• Missing page language declaration

How to become WCAG compliant

There is no shortcut, but there is a clear process:

• 1. Audit your site — Run an automated scan to surface the most obvious issues. Zylyn's free scan takes 90 seconds.
• 2. Prioritize Level A failures — Fix these first. They represent the highest user impact and greatest legal risk.
• 3. Address Level AA — Work through contrast, labels, keyboard traps, and timing issues.
• 4. Test with assistive technology — Screen readers (NVDA, JAWS, VoiceOver) will catch what automated tools miss.
• 5. Document your conformance — Maintain an accessibility statement and, for B2B contexts, a VPAT or ACR.
• 6. Establish a remediation cycle — Run audits on every major release and at least quarterly.