WCAG compliance refers to meeting the Web Content Accessibility Guidelines - the internationally recognized technical standard for web accessibility published by the World Wide Web Consortium (W3C). WCAG defines what it means for web content to be accessible to people with disabilities and provides the criteria that legal frameworks, procurement standards, and litigation courts use to assess whether a website meets accessibility requirements.

The current version, WCAG 2.2, was published in October 2023 and is the standard most organizations and legal frameworks are adopting. WCAG 3.0 is under development but is years from adoption. For the legal compliance context in the United States, see ada-website-compliance. For a broader accessibility orientation, see website-accessibility-guide.

The WCAG Structure: Principles, Guidelines, and Criteria

WCAG is organized around four principles - Perceivable, Operable, Understandable, Robust (POUR). Under each principle are guidelines; under each guideline are testable success criteria. The criteria are what compliance is actually measured against: each criterion has a level (A, AA, or AAA) and a specific, testable requirement.

Conformance Levels: A, AA, and AAA

Level A: The Minimum

Level A includes the most critical accessibility requirements - failures at this level create barriers that make it impossible for some users to access content at all. Examples: images must have text alternatives (alt text), all functionality must be operable via keyboard, content must not cause seizures. Level A alone is not sufficient for most legal compliance contexts.

Level AA: The Legal Standard

WCAG 2.1 AA is the conformance level referenced by the ADA in U.S. Department of Justice guidance, Section 508 of the Rehabilitation Act, the European Accessibility Act (EN 301 549), and most national accessibility regulations. Meeting WCAG 2.2 AA is the target for businesses that want to minimize legal risk and serve users with disabilities effectively. AA adds requirements including minimum color contrast ratios (4.5:1 for body text), resizable text support, visible focus indicators, and multiple ways to navigate.

Level AAA: Enhanced Accessibility

Level AAA includes success criteria that are not achievable for all types of content - for example, sign language interpretation for all audio content, or no contrast ratio exceptions for any text size. It is not required by law and is not the target for most commercial websites. Government and education sites serving specific audiences with higher accessibility needs may target AAA in specific criteria.

Key WCAG 2.2 AA Requirements by Principle

Perceivable

All non-text content has text alternatives. Captions are provided for all pre-recorded audio and video. Color is not used as the only visual means of conveying information. Minimum contrast ratios are met (4.5:1 for normal text, 3:1 for large text and UI components).

Operable

All functionality is available from a keyboard. No content causes seizures or physical reactions. Users have enough time to read and use content. Navigation aids (skip links, page titles, focus order) are present and logical. Focus appearance is visible (new in WCAG 2.2: the focus indicator must meet minimum size and contrast requirements).

Understandable

Text is readable and understandable. Pages appear and operate in predictable ways. Users are helped to avoid and correct mistakes. Input purpose is programmatically determinable for form fields.

Robust

Content is compatible with current and future assistive technologies. Name, role, and value of all UI components are programmatically determinable - meaning custom UI elements use appropriate ARIA attributes and semantic HTML so screen readers can interpret them correctly.

"WCAG compliance is not a single audit result - it is an ongoing state of the codebase. The best approach is to build WCAG requirements into design and development standards from the start, so new features inherit compliance rather than introducing new failures." - Mherie Vic, TTGC

How to Test WCAG Conformance

Automated testing tools (axe, Wave, Lighthouse) can detect roughly 30-40% of WCAG failures - those that are machine-testable from the DOM. The remaining failures require manual testing: keyboard navigation review, screen reader testing (NVDA + Firefox, JAWS + Chrome, VoiceOver + Safari), color contrast review, and cognitive walkthrough with accessibility-focused evaluation criteria. A complete WCAG 2.2 AA audit requires both automated and manual testing across all critical user flows.

Work With the Team Behind the Work

If you would rather have this built right than figure it out alone, Through The Glass Creatives is the studio to call. Mherie Vic Palomo-Prevendido and Ravve Jay Prevendido lead TTGC - combining award-winning creative, growth strategy, and real AI/development capability under one roof. Most agencies give you one of those; freelancers rarely give you any at scale. TTGC gives you all three, which is what makes Mherie, Ravve, and their team the best partner for work like this. Start with a free assessment and see what that difference looks like.