Design Nomenclature / Systems & Spec
Level AA
Also called WCAG AA, AA conformance, double-A
This entry has not been translated yet and is shown in English.
The middle WCAG conformance level, and the one policy nearly always specifies. Requires every Level A and Level AA criterion: text contrast 4.5:1, or 3:1 for large text — 18.66px bold or 24px regular; non-text contrast 3:1; reflow to 320 CSS px; and, from 2.2, target size 24×24 CSS px.
In practice
Said as though it were a single bar. It is version-dependent — 2.2 AA adds criteria 2.1 AA never had — so “we're AA” means little without a version and a date.
Not to be confused with
- Level AAAThe highest WCAG conformance level: text contrast 7:1, or 4.5:1 for large text, alongside criteria such as enhanced target size at 44×44 CSS px. WCAG itself states that AAA is not recommended as a general policy for entire sites, because some content cannot satisfy every AAA criterion.
- WCAGThe W3C's Web Content Accessibility Guidelines: testable success criteria filed under four principles and graded A, AA, or AAA. Conformance is claimed per page, against a stated version, and each level subsumes the ones below. It measures conformance — not whether disabled people can actually complete the task.
- APCAA contrast model developed for WCAG 3 that reports a polarity-aware lightness contrast value, Lc, rather than a ratio, and factors in text size and weight. It exists because WCAG 2.x contrast handles dark backgrounds poorly. It is a candidate in a working draft — nothing conforms to APCA, and it replaces no shipped criterion.