WCAG (Web Content Accessibility Guidelines) is the internationally recognised standard for web accessibility. It defines success criteria at three levels — A, AA and AAA. Most laws and organisations target level AA.
WCAG organises accessibility into four principles (Perceivable, Operable, Understandable, Robust) and testable success criteria at levels A, AA and AAA. AA is the common legal and practical benchmark.
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For business owners
When a contract, regulation or lawsuit references "accessibility", it almost always means WCAG — usually level AA. Knowing the standard lets you set a concrete, defensible target, evaluate vendors, and document your compliance. Aiming for AA covers the vast majority of real user needs and legal expectations.
How it works (technical)
WCAG is built on four principles (POUR):
- Perceivable — text alternatives, captions, contrast.
- Operable — keyboard access, enough time, no seizure-inducing content.
- Understandable — readable, predictable, error-tolerant.
- Robust — works with current and future assistive tech.
Each guideline has success criteria rated A (essential), AA (addresses major barriers) or AAA (highest). WCAG 2.1 and 2.2 add mobile and cognitive criteria. Target 2.2 AA for a modern, defensible baseline.
Real-world example
A supplier bidding for a government contract had to provide a VPAT stating WCAG 2.1 AA conformance. An audit found contrast and focus-order gaps at AA. Fixing those specific criteria let them submit an accurate conformance statement and win the bid.
Why it matters
WCAG is the yardstick behind accessibility law, procurement and audits. Automated scans map many findings to specific WCAG criteria, giving a shared vocabulary for compliance.
How to fix it
Adopt WCAG 2.2 level AA as your target.
Run automated checks to catch common A/AA failures quickly.
Manually test keyboard use, focus order and screen-reader output.
Document conformance (e.g. a VPAT/accessibility statement).
Re-test after significant design or content changes.
Best practices
Target AA; treat AAA as aspirational for specific content.
Combine automated and manual testing.
Keep an up-to-date accessibility statement.
Common mistakes
Claiming conformance based on automated tools alone.
Targeting only level A and missing major barriers.
Treating accessibility as a one-off project rather than ongoing.
Frequently asked questions
Which WCAG level should I aim for?
Level AA. It is the standard referenced by most laws and balances impact with feasibility. AAA is rarely required site-wide.
What is the difference between WCAG 2.1 and 2.2?
WCAG 2.2 adds success criteria (especially around focus, dragging and cognitive load) on top of 2.1. Targeting 2.2 AA is the most current baseline.
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