Goal
Provide error prevention for all user-submitted data.
Success Criterion · WCAG 3.3.6
Error Prevention (All)
For Web pages that require the user to submit information, at least one of the following is true: submissions are reversible, data is checked for input errors and the user is provided an opportunity to correct them, or a mechanism is available for reviewing, confirming, and correcting information before finalizing the submission.
Level AAAWCAG 2.0Understandable3.3 · Input Assistance
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What to do
For any user-submitted information, provide reversible, checked, or confirmed submissions.
Why it matters
Errors can occur in any submission; safeguards reduce harm and rework.
Success criterion
What WCAG 3.3.6 requires
Summarized directly from the official Understanding document so teams can quote the requirement accurately.
For Web pages that require the user to submit information, at least one of the following is true: (1) Reversible. (2) Checked. (3) Confirmed.
Intent
Why WCAG created this requirement
- All submissions benefit from review and correction opportunities.
- This reduces errors and improves user confidence.
- At least one safeguard is required for AAA.
Benefits
Who gains when you pass
- Users with cognitive disabilities can review before submitting.
- Screen reader users can catch mistakes caused by navigation issues.
- All users reduce errors and frustration.
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 submit wrong information with no chance to review.
Users may be forced to contact support to fix mistakes.
Overview
This AAA criterion extends 3.3.4 beyond legal/financial/data changes: for any submission, provide at least one safeguard—undo, validation with correction, or a confirmation/review step.
- Provide a review screen, confirmation step, or undo mechanism for submissions.
- Validation (“checked”) must be clear and actionable (see 3.3.1–3.3.3).
Reference: All summaries and highlights originate from Understanding WCAG 3.3.6 and the W3C quick reference.
Fast facts
- Conformance level
- Level AAA
- 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.
Newsletter signup
Pass
Shows a confirmation step or allows undo/unsubscribe immediately.
Fail
Submits immediately with no confirmation and no way to correct email.
Support ticket
Pass
Review page summarizes details before final submit.
Fail
Instant submit with no review and no edit capability.
Evidence to keep
Document conformance decisions
Capture artifacts for VPATs, procurement reviews, and regression testing.
- Document which safeguard each submission uses and why.
- Capture evidence of review/confirm/undo UI 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
- Audit all forms that submit information.
- Add at least one safeguard (review/confirm/undo) for each submission.
- Ensure safeguards are accessible and preserve user inputs across steps.
- Provide clear success feedback and how to change/correct after submission.
Testing ideas
Prove conformance with evidence
- Submit forms and verify users can review, confirm, or undo.
- Trigger validation errors and confirm users can correct easily.
- Test with keyboard and screen readers for the safeguard flow.
Related success criteria
More from Input Assistance (3.3)
WCAG 3.3.1Error IdentificationLevel AWCAG 3.3.2Labels or InstructionsLevel AWCAG 3.3.3Error SuggestionLevel AAWCAG 3.3.4Error Prevention (Legal, Financial, Data)Level AAWCAG 3.3.5HelpLevel AAAWCAG 3.3.7Redundant EntryLevel AWCAG 3.3.8Accessible Authentication (Minimum)Level AAWCAG 3.3.9Accessible Authentication (Enhanced)Level AAA