Techniques for WCAG 2.0

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ARIA2: Identifying required fields with the "required" property


Technologies that support States and Properties for Accessible Rich Internet Applications.

This technique relates to:

User Agent and Assistive Technology Support Notes

WAI-ARIA is partially supported in Firefox 2.0, which maps roles and properties to platform accessibility APIs. JAWS and Window-Eyes have been successfully tested presenting these properties to the user. FireVox, a self-voicing extension to Firefox, also supports WAI-ARIA via direct DOM access.

At this time, there is not additional user agent support.


The objective of this technique is to indicate that the completion of a user input field is mandatory in a programmatically determinable way. The WAI-ARIA required state indicates that user input is required before submission. The "required" state can have values of "true" or "false". For example, if a user must fill in an address field, then "required" is set to true.

Note: The fact that the element is required is often visually presented (such as a sign or symbol after the control). Using the "required" property makes it much easier for user agents to pass on this important information to the user in a user agent-specific manner.

WAI-ARIA States and Properties is a module supported in XHTML 1.1 and higher, and the specification documents how to provide the properties in XHTML and other XML-based languages. Refer to Embedding Accessibility Role and State Metadata in HTML Documents for information on how to provide WAI-ARIA States and Properties with HTML and XHTML 1.0. WAI-ARIA States and Properties is compatible with other languages as well; refer to documentation in those languages.

Note: at this time, WAI-ARIA is a Working Draft. This technique is provided as an advisory technique for organizations that wish to experiment with achieving WCAG conformance using WAI-ARIA. When WAI-ARIA becomes a formal specification and is supported in user agents, this technique is anticipated to become a sufficient technique.


Example 1: A required text input field in XHTML

The following source code shows an XHTML document using the "required" property to indicate that a form field must be submitted. The mandatory nature of the field is also indicated in the label as a fallback for user agents that do not support ARIA.

Example Code:

<?xml version="1.0" encoding="UTF-8"?>
    For Accessible Adaptable Applications//EN"
<html xmlns="" 
    <title>Required Input</title>
    <h1>Required Input</h1>
    <p>The following form input field must be completed by the user
    before the form can be submitted.</p>
    <form action="">
        <label for="test">Test (required)</label>
        <input name="test" id="test" aaa:required="true" />
        <input type="submit" value="Submit" />


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  1. Access a page with mandatory form fields in a user agent that supports the Accessible Rich Internet Applications specification.

  2. Leaving mandatory form fields empty, attempt to submit the form.

  3. Check that that the user agent notifies of the missing information.

  4. Provide values for the mandatory fields.

  5. Check that the user agent allows form submission to proceed.

Expected Results