What is the Difference Between A, AA and AAA Levels in WCAG?

The Web Content Accessibility Guidelines (WCAG) are organised into three levels of conformance to help developers, designers and content creators meet various degrees of accessibility: Level A, Level AA and Level AAA. These levels are intended to offer a gradient of accessibility that meets different degrees of needs for individuals with disabilities. Here’s an explanation of each:

Level A (Mininum Level)​

Level A is the most basic web accessibility features, which must be satisfied for some users to access web content. Compliance at this level is generally easier to achieve and is considered the minimum standard for accessibility.​

Requirements under this level often include providing text alternatives for non-text content, ensuring that all functionality is available from a keyboard and using basic HTML to structure content and titles correctly.​

Level AA (Mid Range)​

Level AA includes all Level A requirements plus additional provisions that address the biggest and most common barriers for disabled users. This level is typically aimed at making sites accessible to individuals with a wider range of disabilities, including the most common barriers to accessibility.​

Meeting Level AA often involves improving colour contrast, making text resizable without assistive technology by up to 200 percent, providing captions for videos and ensuring consistent navigation across the site. This level is regarded as the gold standard for most websites and is the level often specified as a requirement under laws and regulations.​

Level AAA (Highest Level)​

Level AAA includes all Level A and Level AA requirements plus the highest and most complex level of web accessibility that helps make sites accessible to the greatest extent possible. This level attempts to provide an enhanced accessibility experience but is not required by most policies due to its stringent criteria, which might not be possible to meet for all content or may be deemed over-demanding for some types of content.​

Requirements at this level might include providing sign language interpretation for videos, offering detailed help and guidance for complex or non-standard website functions and ensuring a lower level of background noise for audio content.​

Practical Application

While it is often recommended that websites aim to meet at least Level AA conformance to accommodate legal standards and a broader range of accessibility needs, reaching Level AAA might not be feasible for all content. For instance, it may not be possible to provide detailed documentation or sign language interpretations for all media on a site, especially if resources are limited.​

Each level builds on the previous one, meaning that to achieve Level AA, a site must first meet all Level A criteria. The choice of which level to target depends on several factors, including the audience, legal requirements and organisational capabilities. Most accessibility legislation, such as the Equality Act 2010 require conformance to at least WCAG 2.1 Level AA.

How to Determine Your Website’s Accessibility Level

Ensuring your website meets accessibility standards is crucial for inclusivity and legal compliance. The best way to determine your site’s WCAG 2.2 conformance level (A, AA, or AAA) is through a professional accessibility audit, which identifies key issues like missing alt text, poor colour contrast, lack of keyboard navigability, incorrect form labels and inaccessible multimedia content. Most businesses should aim for Level AA, as it is the legal standard in many regions, including under the Equality Act 2010 in the UK. For websites serving a high proportion of users with disabilities, Level AAA may be beneficial, though it is not always practical for all content types.

To assess accessibility, a combination of automated and manual testing is recommended, using tools like WAVE, Axe and Lighthouse, alongside real screen reader and keyboard navigation tests. Once issues are identified, fixes should be prioritised based on legal compliance, user impact and feasibility within the site’s existing structure. However, accessibility isn’t a one-time fix – it requires ongoing monitoring as content and technology evolve.

Priority Pixels Accessibility Audit Service

Priority Pixels Accessibility Audit service provides a detailed review of your website’s accessibility, helping you meet WCAG 2.2 Level AA compliance and beyond. If you’re unsure about your website’s accessibility level or need expert guidance, please get in touch.