WCAG levels A, AA and AAA explained
WCAG has three cumulative levels: A (essential), AA (the usual target, 55 criteria in WCAG 2.2), and AAA (enhanced, used selectively). Here's how they differ.
WCAG levels: What is the difference between a, AA, and AAA in web accessibility?
The Web Content Accessibility Guidelines (WCAG) have three levels: A, AA, and AAA. Each level builds on the previous one, with Level AA being the most common target for websites.
But what's the difference between them, and which level should your website aim for? Here's what each level means, with practical examples and guidance on choosing the right target.
What are WCAG conformance levels?
WCAG conformance levels are three tiers of accessibility requirements established by the World Wide Web Consortium (W3C). Each level builds on the previous one, meaning a website that meets Level AA must also meet all Level A requirements.
WCAG 2.2 includes 31 Level A requirements, 24 additional Level AA requirements, and 31 additional Level AAA requirements. For a closer look at how conformance is defined, see our accessibility conformance glossary entry.
WCAG A vs AA vs AAA at a glance
The main difference between WCAG A, AA, and AAA is how far each level goes. Level A removes barriers that block access entirely, Level AA removes barriers that make content hard to use for many people, and Level AAA adds stricter requirements for specific situations.
Level | What it covers | Requirements in WCAG 2.2 | Who typically targets it |
|---|---|---|---|
A | The most severe barriers: content some people can't use at all. | 31 | No one should stop here. It's the minimum. |
AA | Everything in Level A, plus barriers that make content hard for many people to use, such as low contrast, text that can't be resized, and invisible keyboard focus. | 24 more (55 in total) | Most organizations. It's the level most accessibility laws and standards reference. |
AAA | Everything in Levels A and AA, plus enhanced requirements such as higher contrast and sign language for video. | 31 more (86 in total) | Specific content, audiences, or tasks, usually by adopting selected requirements. |
What each WCAG level means in practice
Level A: the essential baseline
Level A is the minimum level of WCAG conformance. It addresses barriers that can prevent people with disabilities from accessing or using website content. Examples include:
Providing text alternatives for images.
Making website functionality accessible using a keyboard.
Adding captions to prerecorded videos.
Providing labels and instructions for form fields.
However, Level A doesn't address some of the most common accessibility barriers. For example, insufficient text contrast is covered under Level AA and was the most common issue detected in the WebAIM Million 2026, appearing on 83.9% of the top one million home pages.
Level AA: the practical target for most organizations
Level AA includes everything in Level A, plus additional requirements that make websites easier to use for people with disabilities. Examples include:
Maintaining sufficient contrast between text and its background.
Allowing visitors to resize text without losing information.
Making keyboard focus visible when navigating a website.
Providing sufficiently large, well-spaced buttons and links.
Level AA is the most common accessibility target for organizations and is referenced by many accessibility regulations.
Level AAA: enhanced accessibility
Level AAA includes all Level A and AA requirements, along with additional measures that provide a higher level of accessibility. Examples include:
Higher text contrast requirements.
Sign language interpretation for prerecorded videos.
Larger clickable areas for buttons and links.
Simpler alternatives for content that requires advanced reading abilities.
However, W3C doesn't recommend requiring Level AAA for entire websites because some requirements can't be met for every type of content. Instead, organizations can adopt individual AAA requirements where they benefit their visitors.
How the same page element changes from Level A to AAA
The easiest way to see the difference between the three levels is to follow one website element through each of them.
Website element | Level A | Level AA | Level AAA |
|---|---|---|---|
Color contrast | Don't rely on color alone to communicate information. | Text contrast of at least 4.5:1 for normal text. | Higher text contrast of at least 7:1 for normal text. |
Keyboard navigation | Website functionality must work with a keyboard. | Keyboard focus must be visible. | Additional requirements for focus visibility and appearance. |
Buttons and links | No general minimum target size requirement. | Targets must generally be at least 24 by 24 CSS pixels or meet an exception. | Targets must generally be at least 44 by 44 CSS pixels or meet an exception. |
These are simplified examples, not complete statements of each requirement. In particular, the target size requirements have specific exceptions. For every Level A and AA requirement, see our WCAG 2.2 checklist.
Which WCAG level should you aim for?
For most organizations, aim for Level AA. Use WCAG 2.2 Level AA as a practical current benchmark unless a requirement that applies to your organization names a different version or standard.
Level A alone leaves out barriers that affect many people, such as low contrast and text that can't be resized, and the audience is large: more than 1 in 4 US adults, over 70 million people, reported having a disability in 2022, according to the CDC. Level AAA, on the other hand, works best when it's applied selectively.
A practical way to set your target:
Start with WCAG 2.2 Level AA across your website, including third-party content such as embedded forms, booking tools, and chat windows.
Add AAA requirements where they help your audience most, such as larger tap targets on mobile or plain-language summaries for complex information.
Check which rules apply to your organization, since some reference an older WCAG version or add their own requirements.
Which WCAG level do accessibility laws require?
Many accessibility laws reference WCAG Level AA, although the required WCAG version can differ. Some regulations reference WCAG 2.0 or 2.1, while others don't specify a particular technical standard. WCAG itself is a W3C recommendation, not a law, so meeting a level doesn't on its own mean you meet a legal requirement.
Here are a few examples of how accessibility requirements differ:
Requirement | Who it applies to | What it references |
|---|---|---|
US state and local governments | WCAG 2.1 Level AA | |
US businesses open to the public | No codified technical standard. Courts have applied the ADA to websites more frequently, and outcomes vary by jurisdiction. | |
US federal agencies; vendors are typically held to it through procurement contract terms | WCAG 2.0 Level A and AA | |
Recipients of funding from the US Department of Health and Human Services, such as many healthcare providers | WCAG 2.1 Level AA | |
Covered products and services sold in the EU, including e-commerce | Accessibility requirements supported by EN 301 549. An updated version incorporating WCAG 2.2 was published in 2026, but the legally referenced harmonized version remains based on WCAG 2.1 until the newer standard is formally cited. |
Last reviewed: October 2026. This table is a general overview, not legal advice.
Does the WCAG version change the levels?
No. WCAG 2.0, 2.1, and 2.2 all use the same three levels: A, AA, and AAA.
Each version builds on the previous one by introducing additional accessibility requirements. WCAG 2.2, released in October 2023, added requirements covering areas such as keyboard focus, dragging movements, and accessible authentication (see what's new in WCAG 2.2).
W3C encourages using the latest version, WCAG 2.2, although some accessibility laws still reference earlier versions. WCAG 3.0 is still being developed and will introduce a different approach to measuring accessibility; read more in our WCAG 3.0 explainer.
How to check your website's accessibility
Understanding WCAG levels is one thing. Knowing where your website stands is another. Start identifying accessibility issues with a combination of automated tools and manual testing.
Scan your website for common accessibility issues. Use Clym's free Accessibility Scanner to identify potential barriers, including missing image descriptions, contrast issues, and form fields without labels.
Test your website against WCAG requirements. For a more detailed assessment, Clym's free Accessibility Tools provide automated checks and guided manual testing against WCAG A, AA, and AAA requirements.
Test important website functions manually. Try navigating your website using only a keyboard or a screen reader. Pay particular attention to important tasks, such as filling out forms, signing up, and completing purchases.
Address issues and test again. Prioritize barriers that prevent people from accessing essential content or functionality, then continue working toward your target WCAG level.
Automated tools can identify many accessibility issues, but manual testing is also needed to assess WCAG conformance. Our guide to automated vs manual accessibility testing explains what each approach catches.
The same applies to accessibility widgets and preference tools. They can improve the experience for some visitors, but they don't make a website WCAG-compliant on their own. The content underneath still has to meet the requirements.
Conclusion
WCAG A, AA, and AAA represent three levels of accessibility requirements. Level A is the minimum, Level AA is the practical target for most websites, and Level AAA adds enhanced accessibility requirements.
For most organizations, WCAG 2.2 Level AA is a good starting point, but always check which standards apply to your website.
Frequently asked questions
Not always. Many accessibility regulations reference WCAG Level AA, but the requirements depend on your location and organization. For example, ADA Title II references WCAG 2.1 Level AA for state and local governments, while ADA Title III doesn't specify a technical standard for websites.
Not necessarily. WCAG Level AA addresses many common accessibility barriers, but it doesn't cover every possible user need. Regular testing, including manual testing with assistive technologies, can help identify issues that automated tools may miss.
No. WCAG levels are cumulative, meaning a website must meet all Level A and AA requirements before it can conform to Level AAA.
No. Automated scanners can identify many common accessibility issues, but they cannot determine full WCAG conformance. Manual testing is also necessary to evaluate how people with disabilities interact with your website.
Compliance Content Manager | CIPP/E (IAPP) | CPACC (IAAP)
Alex is a Compliance Content Manager at Clym, where he researches and writes about everything related to data privacy and web accessibility compliance for businesses, helping them stay informed on their compliance needs and spreading awareness about making the web safer and more inclusive. When he's not writing about compliance, Alex has his nose in a book or is hiking in the great outdoors.
