a11y teacher edition W3C WCAG 2.2 & WCAG 3.0 draft reference
Plain English Accessibility Hub

Translating W3C Standards for Designers, Developers, QA & Product teams

โš ๏ธ W3C Working Draft Notice

WCAG 3.0 is an active W3C Working Draft in development by the AGWG. Requirements, assertions, the conformance model and reporting tiers are still being developed and may change. The latest published draft is the 10 September 2026 Working Draft; this site follows the editorsโ€™ draft, which also includes exploratory provisions.

developing Supplemental requirement

Data Entry Validated

Group: error-handling • Guideline: prevent-errors

Summary in Plain English

Data is validated either when the user leaves the field or when the form is submitted - not, for instance, mid-keystroke.

Why It Matters

Validation that fires while someone is still typing produces errors for input that is merely unfinished, which is disorienting for screen reader users and discouraging for people who type slowly.

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