3.3.1 Error Identification (Level A)

When any input error is automatically detected, alert the user, describe the error, and provide instructions on how to correct it.

What you need to know

  • Make input errors easy to find and correct.

What you need to do

  • When a user is filling out a form on your website, for any errors they make that are automatically detected, make it easy for them to correct errors by:
  1. Clearly and specifically identifying any errors that can be detected automatically.
  2. Providing precise instructions on how to fix errors.
  • Offer an example of how to fix an error, for example, “correct date format.”
  • Add a visual indicator to make it easy to find the error.
  • Clearly identify what and where the error is. For example, if someone enters in an incorrect email format (tom@gmailcom), identify the error (incorrect email format), and provide instructions on how to fix it, for example, “Check your email to make sure it is typed correctly.”


Read the full explanation of success criterion 3.3.1 on

Related Resource

Read “Providing text descriptions to identify required fields that were not completed” from W3C’s Web Accessibility Initiative for more information about this success criterion.