WCAG Level A vs AA vs AAA Compared
An evidence-based comparison of the three WCAG 2.2 conformance levels: what each covers, how many criteria each adds, who needs to comply under Australian law, and which level is the right target for your context.
Overview
Which WCAG level should you target?
WCAG 2.2 has three conformance levels: A (30 criteria, essential baseline), AA (adds 25 criteria, the level most legislation requires) and AAA (adds 31 criteria, aspirational). Most Australian organisations target Level AA, which means meeting all 55 Level A and AA criteria combined. The Australian Human Rights Commission and the Digital Service Standard both reference WCAG AA. Level AAA is rarely viable site-wide because some criteria, like sign-language interpretation, cannot reasonably apply to all content.
At-a-glance comparison
Each WCAG level builds on the one before it. A Level AA conformance claim requires that all Level A criteria are also met. A Level AAA claim requires all of A, all of AA, and all of AAA.
| Level A | Level AA | Level AAA | |
|---|---|---|---|
| Criteria added (WCAG 2.2) | 30 | 25 | 31 |
| Total to meet for conformance | 30 | 55 (A + AA) | 86 (A + AA + AAA) |
| What it covers | Removes the most catastrophic barriers: missing alt text, no keyboard access, content that depends on colour alone. | Adds the practical day-to-day experience: contrast, resize, focus indicators, target size, reflow. | Adds aspirational and specialised criteria: enhanced contrast, sign language, reading level, no timing limits. |
| Australian legal context | Minimum that could be argued as reasonable under DDA, but rarely sufficient in practice. | De facto standard. Australian Human Rights Commission and federal Digital Service Standard both point here. Most procurement requires AA. | Not generally required. Selectively used where the criterion applies (health, benefits, specialist services). |
| Realistic to achieve site-wide? | Yes | Yes, with focused effort | No. WCAG itself notes that AAA cannot be satisfied for all content types. |
| Example criteria | 1.1.1 Non-text Content, 1.4.1 Use of Colour, 2.1.1 Keyboard, 3.3.2 Labels or Instructions | 1.4.3 Contrast (Minimum), 1.4.10 Reflow, 1.4.11 Non-text Contrast, 2.4.7 Focus Visible, 2.5.8 Target Size | 1.4.6 Contrast (Enhanced), 1.4.8 Visual Presentation, 2.2.3 No Timing, 3.1.5 Reading Level, 3.3.9 Accessible Authentication (Enhanced) |
| Best for | Personal sites, hobby projects, absolute minimum baseline. | Government, enterprise, banks, universities, healthcare, e-commerce. The default target for Australian organisations. | Specialised audiences (cognitive accessibility, sign-language users), critical content where every barrier removed matters. |
The three levels in detail
Level A: the essential baseline
30 criteria MinimumLevel A removes the most catastrophic accessibility barriers. If a site fails Level A, there are users who literally cannot use it: blind users with no alt text, keyboard-only users with no focus path, deaf users with no captions on critical video. WCAG 2.2 has 30 active Level A criteria. Meeting all of them is the absolute floor for any organisation that claims to take accessibility seriously.
Strengths
- Achievable on any project with reasonable diligence
- Catches the issues most likely to be raised in a Disability Discrimination Act complaint
- Provides the structural foundations (semantics, keyboard, captions) that AA and AAA build on
Limitations
- Does not require colour contrast or visible focus indicators (those are AA)
- Does not require reflow at 320 CSS pixels width (also AA)
- Insufficient on its own for Australian government procurement, AHRC compliance defences, or most enterprise contracts
Level AA: the practical standard
25 added, 55 total StandardLevel AA is what almost every Australian government department, enterprise, university and bank targets. WCAG 2.2 adds 25 criteria at AA, bringing the cumulative total to 55. AA is where the standard becomes usable in real-world day-to-day terms: text is readable, focus is visible, content reflows on mobile and zoom, target sizes are big enough to hit, errors are recoverable. The Australian Human Rights Commission's web accessibility guidance, the federal Digital Experience Policy and most state government procurement policies all point at AA as the conformance target.
Strengths
- Required or strongly recommended by Australian federal and state policies
- Aligns with EN 301 549, Section 508, and most international accessibility legislation
- Genuinely improves the lived experience for users with vision, motor and cognitive disabilities
- Achievable across whole sites with focused remediation work
Limitations
- Substantial work to reach AA from a non-conformant baseline (months to years for large sites)
- Some AA criteria are easy to regress on (contrast, reflow, focus) and need ongoing CI checks
- Does not address every barrier; specialised content may still need AAA-level fixes
Level AAA: aspirational and selective
31 added, 86 total EnhancedLevel AAA is the highest WCAG conformance level and adds 31 criteria, bringing the cumulative total to 86. WCAG 2.2 itself states that AAA conformance cannot reasonably be achieved for all types of content. Some AAA criteria, like 1.2.6 Sign Language and 3.1.5 Reading Level, simply do not apply universally. AAA is therefore typically pursued selectively for high-stakes content: health information, government benefits, banking authentication, content for specific cognitive-accessibility user groups.
Strengths
- Highest possible commitment to inclusive design
- Specific criteria (e.g., enhanced contrast 7:1, no timing limits, plain language) genuinely transform the experience for cognitive and low-vision users
- Strong differentiator for organisations whose users skew toward disability (DPOs, advocacy bodies, accessibility-focused services)
Limitations
- Cannot be achieved site-wide for most content
- Some criteria are subjective (reading level, contextual help) and contested in audit
- Marginal cost-benefit for organisations whose users are not specifically AAA-sensitive
Which level should you target?
For almost every Australian organisation, the answer is AA. The exceptions are usually about targeting AAA selectively for specific content, not lowering to A.
Common questions
Is WCAG Level AA legally required in Australia?
WCAG itself is a technical standard, not a law. In Australia the binding obligations come from the Disability Discrimination Act 1992 and the Australian Human Rights Commission's guidance, both of which point to WCAG as the practical benchmark. The Australian Government Digital Experience Policy requires Level AA conformance for federal government websites. State and territory accessibility policies, NSW and Victoria included, also reference WCAG 2.2 AA. So while no statute names a specific level, AA is the de facto standard for any organisation that needs to demonstrate compliance.
What happens if I only meet Level A?
Level A on its own is widely considered insufficient. It removes the most catastrophic barriers but leaves substantial gaps in colour contrast, resize behaviour, focus indicators, target size and other areas that genuinely affect day-to-day use. In a Disability Discrimination Act complaint, an organisation meeting only Level A would have difficulty arguing it has taken reasonable steps. For procurement, most government and enterprise contracts require Level AA at minimum and many will mark a Level A response as non-compliant.
Should we target Level AAA?
WCAG 2.2 itself warns that it is not possible to satisfy Level AAA across all types of content. Some AAA criteria, like 1.2.6 Sign Language and 3.1.5 Reading Level, simply cannot be applied universally. AAA is a target for specific content types where the criterion can be met, not a site-wide goal. Where to apply AAA selectively: health and benefits services (reading level, plain language), authentication flows (3.3.9 enhanced), and content for users with significant cognitive disability or sign-language preference.
How long does it take to reach WCAG AA?
It depends on the starting point. For a small marketing site built on a modern framework with good practices, a few weeks of focused remediation plus design system updates is typical. For a large enterprise site with thousands of pages, multiple frameworks, and PDF artefacts, expect a multi-year program: audit, remediation roadmap, training, embedded specialists, and ongoing governance. Australian government departments commonly run 18 to 36 month programs to reach AA across all their digital channels.
Can a site meet Level AA but fail individual Level A criteria?
No. AA conformance requires that the site meets all Level A criteria plus all Level AA criteria. The levels are cumulative: AA includes A. Similarly, AAA requires A plus AA plus AAA. A single failed Level A criterion means a Level AA conformance claim is not valid. This is why audit reports list findings by severity, not by level alone, so teams can fix the worst issues first regardless of which level they sit at.
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