Understanding Success Criterion 3.3.3: Error Suggestion

Success Criterion 3.3.3 Error Suggestion (Level AA): 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

The intent of this Success Criterion is to ensure that users receive appropriate suggestions for correction of an input error if it is possible. The WCAG 2.0 definition of "input error" says that it is "information provided by the user that is not accepted" by the system. Some examples of information that is not accepted include information that is required but omitted by the user and information that is provided by the user but that falls outside the required data format or allowed values.

Success Criterion 3.3.1 provides for notification of errors. However, persons with cognitive limitations may find it difficult to understand how to correct the errors. People with visual disabilities may not be able to figure out exactly how to correct the error. In the case of an unsuccessful form submission, users may abandon the form because they may be unsure of how to correct the error even though they are aware that it has occurred.

The content author may provide the description of the error, or the user agent may provide the description of the error based on technology-specific, programmatically determined information.

Benefits

Examples

Related Resources

Resources are for information purposes only, no endorsement implied.

Techniques

Each numbered item in this section represents a technique or combination of techniques that the WCAG Working Group deems sufficient for meeting this Success Criterion. However, it is not necessary to use these particular techniques. For information on using other techniques, see Understanding Techniques for WCAG Success Criteria, particularly the "Other Techniques" section.

In some cases, more than one of these situations may apply. For example, when a mandatory field also requires the data to be in a specific format.

Sufficient Techniques

Select the situation below that matches your content. Each situation includes techniques or combinations of techniques that are known and documented to be sufficient for that situation.

Situation A: If a mandatory field contains no information:

  1. Providing a text description that identifies the field as mandatory
  2. ARIA2: Identifying required fields with the "required" property
  3. PDF5
  4. SL35

Situation B: If information for a field is required to be in a specific data format:

  1. ARIA18
  2. Providing a text description when user input falls outside the required format or values
  3. Providing suggested correction text
  4. SCR18: Providing client-side validation and alert
  5. Providing client-side validation and adding error text via the DOM
  6. Providing client-side validation and adding error text via the accessible description
  7. PDF22

Situation C: Information provided by the user is required to be one of a limited set of values:

  1. ARIA18
  2. Providing a text description when the user provides information that is not in list of allowed values
  3. Providing suggested correction text
  4. SCR18: Providing client-side validation and alert
  5. Providing client-side validation and adding error text via the DOM
  6. Providing client-side validation and adding error text via the accessible description
  7. PDF22

Advisory Techniques

Although not required for conformance, the following additional techniques should be considered in order to make content more accessible. Not all techniques can be used or would be effective in all situations.

  • G139: Creating a mechanism that allows users to jump to errors
  • Making error messages easy to understand and distinguishable from other text in the Web page (future link)
  • Validating form submissions on the server (future link)
  • When mandatory information has not been provided, including descriptions or examples of correct information in addition to identifying the field as mandatory (future link)
  • Repeating and emphasizing suggestions for correcting each input error in the context of its form field (future link)
  • Providing a way for the user to skip from each item in a list of suggestions to its corresponding form field (future link)
  • Providing additional contextual help for the form field requiring change (future link)
  • Accepting input data in a variety of formats (future link)
  • Providing success feedback when data is submitted successfully

Techniques for providing suggestions to the user (Advisory)

  • Providing a text description that contains information about the number of input errors, suggestions for corrections to each item, and instructions on how to proceed (future link)
  • Providing a text description that contains suggestions for correction as the first item (or one of the first items) of content, or emphasizing this information in the content (future link)
  • Displaying errors and suggestions in the context of the original form (for example, re-displaying a form where input errors and suggestions for correction are highlighted and displayed in the context of the original form) (future link)

HTML Techniques (Advisory)

  • Providing "correct examples" for data and data formats as initial text in mandatory form fields (future link)
  • Providing links to suggested correction text "close to" form fields, or providing the suggested correction text itself directly on the Web page "next to" form fields (future link)

Client-Side Scripting Techniques (Advisory)

  • Providing client-side validation and alert
  • Providing client-side validation and adding error text via the DOM (future link)
  • Calling a function from the submit action of a form to perform client side validation (future link)

Failures

The following are common mistakes that are considered failures of this Success Criterion by the WCAG Working Group.

Key Terms

input error

information provided by the user that is not accepted

This includes:

  1. Information that is required by the Web page but omitted by the user
  2. Information that is provided by the user but that falls outside the required data format or values