WCAG conformance levels A, AA and AAA

WCAG defines three conformance levels — A, AA and AAA. They are not a simple ladder where higher is always better for every situation. Each level adds a further set of success criteria on top of the one below it. Australian guidance names a specific level as the practical benchmark, rather than the highest one available.

The three WCAG conformance levels, in outline: Level A, Level AA and Level AAA

Level	What it represents	Practical implication
A	The minimum set of success criteria	Failing Level A usually means some people cannot use part of the site at all
AA	Level A plus a further set of criteria	The level named in Australian guidance as the practical benchmark
AAA	Level A and AA plus the most stringent additional criteria	Not intended to be met across an entire site’s content, per the W3C’s own guidance

Why WCAG Level AA is the digital accessibility standards benchmark that matters in Australia

In April 2025 the Australian Human Rights Commission replaced its long-standing World Wide Web Access advisory notes with the Guidelines on Equal Access to Digital Goods and Services, which name WCAG 2.2 Level AA as the minimum benchmark, extending scope beyond websites to mobile applications, AI-driven tools, connected devices and self-service machines such as kiosks and ticketing terminals. These guidelines are guidance rather than law — the legal obligation itself comes from the Disability Discrimination Act, covered in full on website accessibility in Australia — but they are the clearest published statement of what the Commission considers equal access to require, and they supersede the older, narrower advisory material some suppliers still reference.

Why AAA is not the safer, more thorough option it sounds like: not every success criterion can be met

The W3C states explicitly that it is not recommended as a general policy for entire sites. Some AAA success criteria cannot be satisfied for certain types of content, no matter how the content is designed. Some AAA criteria around sign language interpretation for all video content, for instance, are not achievable for every kind of site or organisation. A supplier who promises full AAA conformance across an entire site is either unaware of this limitation, or is overselling a claim the specification itself says shouldn’t be made blanket. Individual AAA criteria can still be worth adopting selectively, where they’re achievable and genuinely improve the experience. The issue is treating AAA as a wholesale target, rather than a selective one.

What actually changes between Level A and Level AA in the Web Content Accessibility Guidelines

Level A covers the most fundamental barriers. This is content that genuinely cannot be perceived or operated at all by some users. Level AA adds requirements addressing barriers that are less absolute but still substantial. A specific minimum contrast ratio, rather than merely “some contrast,” is one example. Additional requirements around resizing text, consistent navigation, and more complete keyboard operability are others. The gap between A and AA is where most of the genuinely useful, achievable accessibility improvement sits for an ordinary business website.

Why a supplier’s claimed conformance level is worth verifying, not just asking about

Ask specifically which WCAG version and level a supplier builds to. Treat the answer as a starting claim to verify, rather than a guarantee. Automated tools can check only a portion of WCAG’s success criteria — covered in full on what automated scanners can and cannot find. A supplier’s stated conformance level is a useful commitment to have in writing in a contract. But it is not, on its own, proof the criteria have actually been met.

Where WCAG standards connect to your build brief

State the target WCAG version and level explicitly in your written brief and contract, rather than leaving “accessible” undefined — the vagueness that produces disputes later almost always traces back to a term left unspecified at the brief stage, covered more generally on what a web design contract should deal with.

Why conformance is assessed per page, not for a whole site as a single verdict

WCAG conformance is technically defined at the level of an individual web page, not as a single verdict covering an entire website. A site can have some pages meeting Level AA and others falling short. A genuine conformance assessment should identify this variation, rather than producing one blanket statement about the whole site. Be sceptical of any claim that an entire multi-page site is “Level AA compliant” as a single fact, without qualification about which pages were actually assessed.

Why some criteria are easier to reach AA on than others

Within Level AA, some success criteria are close to binary and straightforward to meet correctly — a specific contrast ratio, for instance. Others require more judgement and design consideration, such as ensuring consistent navigation across a whole site, or that error messages are genuinely helpful rather than technically present. A site can score well on the easier, more mechanical criteria while still falling short on the more judgement-dependent ones. That is part of why a single pass/fail summary understates the real picture.

The relationship between conformance level and legal risk, stated carefully

Meeting WCAG 2.2 Level AA is not itself a legal defence under the Disability Discrimination Act — the Act’s test is about discrimination in the provision of a service, not conformance with a technical standard — but a business demonstrably working toward and largely meeting Level AA is generally in a much stronger practical position than one that has never considered the standard at all. This is general information, not legal advice, and the actual legal position for a specific business is a question for a lawyer.

Digital accessibility standards beyond a single success criterion

WCAG is only one part of the broader digital accessibility standards landscape a business may need to consider — audio and video content, PDFs, and third-party embedded tools each carry their own considerations beyond the core web content criteria discussed above. Treating “WCAG conformance” as the whole of digital accessibility, rather than the core of it, understates what a genuinely accessible experience actually requires.

Common questions about WCAG compliance

What is WCAG compliance? WCAG — the Web Content Accessibility Guidelines — defines three conformance levels of success criteria (A, AA and AAA) a website should meet so people with disability can use it. “WCAG compliance” usually means meeting Level AA, which the Australian Human Rights Commission’s April 2025 guidelines name as the benchmark. Conformance is assessed per page, not as a single site-wide verdict.

What WCAG level should an Australian business website target? The Australian Human Rights Commission’s Guidelines on Equal Access to Digital Goods and Services, published April 2025, name WCAG 2.2 Level AA as the benchmark. This is guidance, not a statute, but it is the clearest published statement of what the Commission considers equal access to require.

Should a business aim for AAA to be extra safe? No — the W3C itself states AAA is not intended to be achievable across an entire site’s content, and a supplier promising blanket AAA conformance is either mistaken or overselling.

What to do next

State WCAG 2.2 Level AA explicitly as the target in your brief and contract, rather than accepting “accessible” as an unspecified aspiration, and treat AAA as a selective enhancement rather than a realistic whole-site target. A structured way to gauge where a site currently stands against these levels, without relying on an automated pass mark, is the accessibility self-assessment.