Goal
Help users recover from errors by suggesting fixes.
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3.3.2 Labels or Instructions
Level A
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3.3.4 Error Prevention (Legal, Financial, Data)
Level AA
Success Criterion · WCAG 3.3.3
Error Suggestion
If an input error is automatically detected and suggestions for correction are known, then the suggestions are provided to the user, unless it would jeopardize the security or purpose of the content.
Level AAWCAG 2.0Understandable3.3 · Input Assistance
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What to do
When you detect an input error and can suggest a correction, provide that suggestion.
Why it matters
Users may not know how to fix an error; suggestions reduce frustration and improve completion.
Success criterion
What WCAG 3.3.3 requires
Summarized directly from the official Understanding document so teams can quote the requirement accurately.
If an input error is automatically detected and suggestions for correction are known, then the suggestions are provided to the user, unless it would jeopardize the security or purpose of the content.
Intent
Why WCAG created this requirement
- Error suggestions help users correct problems quickly.
- Security-sensitive contexts may limit how specific suggestions can be.
- Suggestions should be clear and actionable.
Benefits
Who gains when you pass
- Users with cognitive disabilities can fix errors with less trial-and-error.
- Screen reader users get actionable guidance, not just an error state.
- All users complete forms faster with clear correction hints.
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 repeatedly fail without knowing the expected format or constraints.
Users may abandon tasks due to unclear errors.
Exception guidelines
Use the WCAG 3.3.3 exceptions correctly
Document the rationale for each exception and note which alternative support you provide.
Security/purpose
Suggestion would jeopardize security or purpose.
Requirement
Avoid overly specific suggestions in sensitive authentication flows.
Overview
When validation fails and you can recommend how to fix it (like “Password must be at least 12 characters”), provide that suggestion. Do not provide suggestions when it would compromise security (e.g., revealing which part of a secret is wrong).
- Provide specific, actionable suggestions (“Use digits and symbols”).
- For security, avoid revealing whether username exists or which factor failed.
- Associate suggestion text with the input (or error summary) for AT.
Reference: All summaries and highlights originate from Understanding WCAG 3.3.3 and the W3C quick reference.
Fast facts
- Conformance level
- Level AA
- 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.
Password rule
Pass
“Password must be at least 12 characters and include a number.”
Fail
“Invalid password” with no guidance.
Email format
Pass
“Enter an email address like name@example.com.”
Fail
“Email invalid” with no example.
Evidence to keep
Document conformance decisions
Capture artifacts for VPATs, procurement reviews, and regression testing.
- Document the set of validation rules and their suggested fixes.
- Record security policy for error messaging (what we do/don’t reveal).
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
- Define validation rules and pair each with a clear correction suggestion.
- Display suggestion near the field and associate programmatically.
- Add error summary suggestions for multi-field forms.
- Review authentication flows for security-safe messaging.
Testing ideas
Prove conformance with evidence
- Trigger validation errors and confirm suggestions appear when applicable.
- Use a screen reader to verify suggestions are announced with the error.
- Review security-sensitive errors for safe messaging.
Related success criteria
More from Input Assistance (3.3)
WCAG 3.3.1Error IdentificationLevel AWCAG 3.3.2Labels or InstructionsLevel AWCAG 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