On Mastodon, Steve Faulkner shared a link to a GitHub discussion around the A, AA, and AAA levels of WCAG (Web Content Accessibility Guidelines). In it, the question is asked what makes a Success Criterion (SC) A, AA, or AAA. Basically, the question is what criteria are used to decide the level for any specific Criterion.

The “Understanding Levels of Conformance” section in the Understanding documents explains which considerations contributed to the decision for each criterion (paraphrased):

• Is this SC essential for access overall?
• Can the SC be achieved by all websites and apps?
• How easy is it to learn or address the issues that this SC uncovers?
• Will meeting the SC require changes to the design or functionality of the site or app?
• Is it possible to work around requirements?

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I'm a web accessibility professional who cares deeply about inclusion and an open web for everyone. I work with Axess Lab as an accessibility specialist. Previously, I worked with Knowbility, the World Wide Web Consortium, and Aktion Mensch. In this blog I publish my own thoughts and research about the web industry.

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Importantly, not all criteria apply to all Success Criteria. But here are some examples:

• 2.1.1 Keyboard is Level A despite the effort it can take to implement keyboard navigation and the occasional impact on design and functionality because keyboard access is absolutely fundamental for accessibility. There are very limited workarounds when keyboard access is unavailable.
• 1.4.5 Images of Text is Level AA because it can change the design, it can sometimes be difficult to change from an textual image to “real text”, depending on the tools used, and text alternatives (and more recently OCR) can be valid workarounds.
• 1.2.6 Sign Language (Prerecorded) is Level AAA because recording and embedding sign language information can be a significant effort and is probably unrealistic for many websites (for example news sites that are frequently updated). Most sign language users can also perceive written information.

While this is easy enough to do when creating the SCs, the levels lose their usefulness when clients try to use them as signifiers of what is more important. Because the reality is: everything on the level you want to conform to is equally critical.

The Levels are also the result of a political discussion during the creation of WCAG, there is some amount of back and forth that happens when new SCs are introduced, and the group needs to come to a consensus. A W3C member might feel strongly that an SC is so difficult to implement that it should be Level AAA. The group has only two options: Try to change the SC until the member agrees to move it to a lower level, or accept the AAA designation.

In practice, it makes almost no difference for disabled people in which order issues are fixed, with the following exception:

Non-interference SCs are four SCs that are listed in WCAG that create barriers so significant, that they affect the ability to use the page overall. Those SCs are (order as in WCAG):

• 1.4.2 Audio Control
• 2.1.2 No Keyboard Trap
• 2.3.1 Three Flashes or Below Threshold
• 2.2.2 Pause, Stop, Hide

So, if anything, failures concerning those SCs should have preference over others. As for the A/AA distinction, it’s mostly academic: Most would agree that conforming only to Level A is not good enough to ensure that most disabled users have basic access. Level AA (which means meeting all Level A and AA criteria) is widely considered the absolute baseline. And that includes laws and policies around the world.

In my final talk, “Web Accessibility is broken. It’s time to fix it.”, I proposed gentle WCAG reform (instead of the W3CAG revolution). Video here. My suggestions included combining the A and AA Levels.

AAA Level SCs should be checked if they are more achievable today than when they were introduced and either imported into the standard (making them A/AA) or exported into modules that individual websites could then choose to conform to.

For the above-mentioned Sign Language Success Criterion, websites would conform to WCAG 2.5+Sign Language. The modules could be listed in the accessibility statement of the site, and users who need the information would know better which features they could expect.

This approach would also allow getting rid of some redundant success criteria: 1.2.3 Audio Description or Media Alternative (Prerecorded) (Level A) requires a audio description or a transcript with described audio, while 1.2.5 Audio Description (Prerecorded) (Level AA) requires audio description, essentially removing the option to use a descriptive transcript instead.

Similarly, another contested issue could be simplified: 3.3.2 Labels or Instructions (Level A) technically only requires that labels need to be present, 2.4.6 Headings and Labels (Level AA) requires that the labels are also actually descriptive. In practice, because most conformance is aiming at Level AA anyway, labels need to be descriptive¹ .

In my trainings, I only teach levels as conformance levels and not really elaborate on individual SCs Level rating. When I point out what the Conformance Levels do, my short, easy to learn explanation is:

• A: Removes many barriers for many disabled people.
• AA: Removes most barriers for most disabled people.
• AAA: Removes additional barriers.

It’s not the most clear and comprehensive way to phrase it. But it gives student’s enough to not worry about individual levels. It also helps explain why A conformance is not enough, and AA conformance does not mean that your website/app is “accessible”.