WCAG Levels of Conformance: Understanding A, AA, and AAA

What Do WCAG Levels of Conformance Actually Mean?

If you're working to make your website accessible, you've likely encountered the terms WCAG Level A, AA, and AAA — but what do these levels really mean?

The Web Content Accessibility Guidelines (WCAG) are the global gold standard for digital accessibility, providing a framework for making content more usable by everyone, including people with disabilities. The guidelines are divided into three levels of conformance, each representing a different degree of accessibility.

This blog explains:

• What each WCAG conformance level entails
• The differences between Level A, AA, and AAA
• Which level is required by law or best practice
• Real-world examples and practical steps to achieve compliance

Let’s decode the jargon and get clear on what these levels mean for your website.

What Are WCAG Conformance Levels?

WCAG conformance levels help organizations measure how well their websites and applications support accessibility. Each level builds upon the previous one, increasing in complexity and inclusivity.

The Three WCAG Conformance Levels:

WCAG Level A: The Essential Foundation

Level A is the baseline. It eliminates the most critical barriers but doesn't provide full accessibility for all user groups.

Examples of Level A Requirements:

• All images must have alt text
• Pages must be navigable using a keyboard
• Video content must not autoplay with sound
• HTML must follow semantic structure

Note:
Level A alone is not sufficient for legal compliance in most regions (e.g., under AODA, ACA, or ADA).

WCAG Level AA: The Industry Standard

Level AA is the most widely adopted and legally required conformance level in many countries. It balances inclusivity with practicality.

Key Level AA Requirements:

• Text must have sufficient color contrast (minimum 4.5:1)
• Content must be resizable up to 200%
• Navigation must be consistent across pages
• Input errors must be clearly identified and described

Who Should Aim for Level AA?

• Government bodies (required in the US, Canada, EU)
• Enterprises and public-facing businesses
• Anyone seeking to meet accessibility laws

WCAG Level AAA: The Gold Standard (But Not Always Practical)

Level AAA includes the most advanced and comprehensive accessibility practices. While ideal, it’s not always feasible to meet every AAA requirement, especially for large, complex websites.

Level AAA Includes:

• Sign language interpretation for all video content
• No timing restrictions unless essential
• Live audio content must have real-time captions
• Reading level must be understandable by a wide audience

Note: 
No law requires full AAA compliance, and even W3C acknowledges that it’s not practical for all web content.

Comparison Table: WCAG A vs AA vs AAA

Real-World Example: WCAG AA in Action

Air Canada, under the Accessible Canada Act, revamped its digital booking platform to comply with WCAG 2.1 Level AA. Changes included:

• Enhanced color contrast
• Clear error handling in form fields
• Keyboard navigable menus
• Alt text for every image in the booking flow

Result? Improved user satisfaction and a significant reduction in accessibility-related complaints.

Pro Tip: Don’t Aim for Perfection, Aim for Progress
Accessibility is an ongoing journey. Even reaching Level AA doesn’t mean you’re done. Maintain accessibility by:

• Regularly testing with tools like axe DevTools, WAVE, and Accessibility Insights
• Involving people with disabilities in usability testing
• Keeping up with WCAG updates (e.g., WCAG 2.2 and the upcoming WCAG 3.0)

Conclusion: 

For most organizations, WCAG 2.1 Level AA is the sweet spot — balancing legal compliance, inclusivity, and practical implementation.

Level A is a start, but it’s not enough. Level AAA is admirable, but rarely feasible. The best approach? Start with AA, then enhance over time as your accessibility maturity grows.