All WCAG criteria
WCAG 3.3.1 · UnderstandableLevel A

3.3.1Error Identification

When a user input is detected as invalid, the error must be identified and described to the user in text.

Common failures

Patterns that fail this criterion.

  • 01Form errors shown as red border only, no text
  • 02Single page error like "Please correct the highlighted fields" with no specifics
How to test

Testing approach: manual.

Manual — submit invalid data; confirm errors are described in text near the offending field.

How to fix

Remediation steps.

  1. 1

    Per-field error text

    Place an error message next to each failing field. "Email must include @" not just "Invalid".

  2. 2

    Use aria-invalid + aria-describedby

    Screen readers announce the error when the field receives focus.

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Related criteria

Often appears with…

WCAG 3.3.3 · Level AA

Error Suggestion

All 50 WCAG 2.1 Level A + AA success criteria explained.

View the full checklist