What is the difference between WCAG A, AA and AAA levels of compliance?
Learn the main differences between each level of compliance.
The Web Content Accessibility Guidelines (WCAG), developed by the W3C, provide a framework for creating Web pages that are accessible to all people, including those with disabilities. These standards are organized into three levels of conformance, from most basic to most comprehensive: A, AA and AAA.
🟢 Level A (Minimum Conformance)
This level establishes the essential requirements for a site to be accessible:
- Mandatory use of alternative text (alt) on all images.
- Provision of descriptive transcripts for prerecorded audio or video media.
- Correct use of structured headers.
- Inclusion of ARIA tags in key places.
- Avoid elements such as <div> or <span> for interactive features; instead, use semantic elements such as <button> or <a>.
- Content should be presented in a coherent and meaningful way.
- Do not rely exclusively on color, shape, size, or sound to convey information.
- Avoid automatic media playback without user control.
- Allow full keyboard navigation.
- Ability to pause, stop or hide animated content.
- Avoid content that flashes more than 3 times per second.
- Do not include irrelevant or misleading links.
- Correctly label form fields, using visible labels or ARIA attributes.
This level provides a solid foundation for accessibility, eliminating common barriers.
🔵 Level AA (Recommended)
In addition to complying with level A, this includes enhancements focused on user experience:
- Closed captioning for live content, and video narration.
- Content must be accessible in both landscape and portrait mode on mobile devices.
- Color contrast should be at least 4.5:1 for normal text and 3:1 for large text or graphic elements.
- When focusing or hovering over elements, they should appear without overlapping others.
- The site should include a clear navigational structure, such as a site map, table of contents, or related links.
- Each page should have unique titles and descriptive labels.
- Keyboard focus should be highly visible and consistent.
- Repeating elements should maintain a consistent order.
- To convey status messages, ARIA live regions should be used.
- Forms should have clear labels, and navigation should be simple.
AA level is the primary goal of many organizations and also the legal standard in several countries.
🔴 Level AAA (High Accessibility)
Includes all of the above requirements and adds even more stringent criteria:
- Streaming media must include sign language interpretation and accurate audio description.
- Avoidance of unnecessary background sound is recommended.
- The contrast between text and background should be at least 7:1.
- Links should be clear in themselves, without relying on context.
- Headings should clearly describe the structure and content of the page.
- All interaction should be keyboard-only.
- Include tools to change the color or increase the size of the text.
- Abbreviations, idioms and technical terms should be explained with a glossary or contextual help.
- Avoid any content with flickering or flashing.
- No time limits should be imposed on the use of the site.
- The text should be at an accessible reading level, avoiding unnecessary technicalities.
This level is ideal for projects seeking impeccable accessibility, although it can be complicated to implement on large or existing sites.
🤔 Why are these levels important?
- They improve the experience for all users, not just those with disabilities.
- They strengthen SEO, as they are desirable to search engines.
- They increase retention and conversion by being more understandable and easier to use.
- Reduce legal risks, since many regulations require at least AA level.
Conclusion
Achieving at least AA is a solid and strategic goal for most projects. Meeting AAA, while admirable, is often feasible in new phases or sites designed from the ground up with inclusion as a focus.
At Inclusif, we help companies, developers and designers audit, correct and certify their websites to WCAG standards. With our practical and human approach, we turn accessibility from a technical task into a competitive advantage.
👉 Contact us today and find out how we can help you achieve a truly accessible website.