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.
developingSupplemental 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.