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WCAG 2.1 Criteria Documentation

3.3.3 Error Suggestion (Level AA)

High-Level Description

When users make an error, they must be provided with clear suggestions on how to correct it.

Detailed Description

This success criterion requires that if an input error is detected and known, users are provided with suggestions for correction - helping them understand how to fix the issue and complete their task successfully.

Applies to:

  • Forms requiring user input or submission
  • Inputs where user errors are common, such as incorrect format and required fields
  • Any interface where information must be entered correctly to proceed

This allows:

  • Users to understand not just what is wrong, but how to fix it
  • Reduced frustration from vague error messages
  • Increased success for users with cognitive, language, and memory-related disabilities

Indicators of Non-Compliance:

  • Error message simply says "Invalid input" with no further detail
  • A required field error shows "Field is required" but doesn't specify what to enter
  • The form resets or blocks progress without offering any correction guidance
  • Field shows an error but no information about the expected format or content

Real-World Examples

ScenarioNon-CompliantCompliant
Email field left empty The error given is: "Invalid input.""Please enter your email address. Example: name@example.com"
Passwords don't matchThe error given is: "Error in form submission.""Passwords do not match. Please ensure both entries are identical."
Date format incorrectThe error given is: "Error.""Enter your date of birth in MM/DD/YYYY format (e.g., 07/14/1992)."
Credit card number is invalidThe error given is: "Invalid card number.""Card number must be 16 digits, numbers only."
Username already takenThe error given is: "Invalid input.""That username is already taken. Try adding numbers or choosing a different one."

Disability Impact

Disability GroupWithout ComplianceWith Compliance
Cognitive DisabilitiesVague or missing error suggestions lead to confusion and abandonment.Clear suggestions help users understand and complete tasks.
Screen Reader UsersGeneric errors offer no context or next steps.Screen reader announces what's wrong and what to do.
Low Literacy / Language LearnersMay struggle to interpret vague or technical errors.Plain language suggestions improve understanding.
All UsersRepeated failed attempts or incomplete submissions.Better success rate and confidence in using forms.

Supporting Documentation

Remediation Strategies

    Error messages should clearly explain what is wrong and how to fix it, using specific instructions or examples:

    < span class="error" role="alert" >Phone number must include area code and contain only digits.< /span >

    When errors occur, offer informative next actions, such as "Try again", "Check your spelling", or "Contact support".

    Avoid overly technical messages, make suggestions helpful and easy to understand for a wide range of users.