Goal
Ensure users can tell when a form input has an error.
Success Criterion · WCAG 3.3.1
Error Identification
If an input error is automatically detected, the item that is in error is identified and the error is described to the user in text.
Level AWCAG 2.0Understandable3.3 · Input Assistance
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What to do
Identify errors in text (and programmatically) rather than relying only on color or position.
Why it matters
Users who can’t perceive visual cues need explicit error identification to fix problems and complete tasks.
Success criterion
What WCAG 3.3.1 requires
Summarized directly from the official Understanding document so teams can quote the requirement accurately.
If an input error is automatically detected, the item that is in error is identified and the error is described to the user in text.
Intent
Why WCAG created this requirement
- Errors must be communicated in text, not only via color or styling.
- Users must be able to locate the field in error.
- Programmatic association helps screen readers announce errors at the right time.
Benefits
Who gains when you pass
- Screen reader users can understand what went wrong and where.
- Color-blind users can identify errors without relying on red/green cues.
- Users with cognitive disabilities benefit from clear, explicit error messages.
Why it matters
User impact when this criterion fails
Summaries drawn from the Understanding document help you socialize impact statements with product stakeholders.
Users may be blocked from submission without knowing why.
Users may repeatedly fail validation because the error is not discoverable.
Users may abandon forms due to confusion and frustration.
Overview
When validation detects an error, clearly identify which field is wrong and describe the error in text. Do not rely only on a red border or an icon. Also ensure assistive technologies can identify the error association (e.g., `aria-invalid`, `aria-describedby`).
- Place error messages near the relevant field and ensure they are readable.
- Use `aria-invalid="true"` and `aria-describedby` pointing to the error text.
- Provide an error summary at the top for multi-field forms and move focus to it when appropriate.
- Ensure errors are announced in a live region if shown dynamically after interaction.
Reference: All summaries and highlights originate from Understanding WCAG 3.3.1 and the W3C quick reference.
Fast facts
- Conformance level
- Level A
- WCAG version introduced
- WCAG 2.0
- Principle
- Understandable
- Guideline
- 3.3 · Input Assistance
Examples
Make success tangible for teams
Share pass/fail snapshots to coach designers, engineers, QA, and content authors.
Required field
Pass
“Email is required” appears next to the Email field and is referenced via `aria-describedby`.
Fail
Only a red border is shown with no message.
Error summary
Pass
Top-of-form summary lists errors and links to each invalid field.
Fail
Errors are scattered with no way to find them quickly.
Evidence to keep
Document conformance decisions
Capture artifacts for VPATs, procurement reviews, and regression testing.
- Document validation rules and the corresponding error message copy.
- Capture screenshots of error states and error summaries for audits.
Official resources
Deep dives and supporting material
Keep these links handy when writing acceptance criteria or responding to audits.
Implementation checklist
Capture progress and blockers
- Add clear, specific error text for each validation rule.
- Associate errors with inputs programmatically (`aria-describedby`, `aria-invalid`).
- Provide an error summary for multi-field forms with links to fields.
- Avoid color-only error indicators; use icons/text and accessible naming.
- Ensure focus management supports quickly reaching the first error.
Testing ideas
Prove conformance with evidence
- Submit forms with invalid inputs and verify errors are shown in text.
- Use a screen reader to confirm the field and its error are announced.
- Verify error indicators do not rely solely on color.
- Check the accessibility tree for `aria-invalid` and description linkage.
Related success criteria
More from Input Assistance (3.3)
WCAG 3.3.2Labels or InstructionsLevel AWCAG 3.3.3Error SuggestionLevel AAWCAG 3.3.4Error Prevention (Legal, Financial, Data)Level AAWCAG 3.3.5HelpLevel AAAWCAG 3.3.6Error Prevention (All)Level AAAWCAG 3.3.7Redundant EntryLevel AWCAG 3.3.8Accessible Authentication (Minimum)Level AAWCAG 3.3.9Accessible Authentication (Enhanced)Level AAA