Techniques for WCAG 2.0

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H36: Using alt attributes on images used as submit buttons

Important Information about Techniques

See Understanding Techniques for WCAG Success Criteria for important information about the usage of these informative techniques and how they relate to the normative WCAG 2.0 success criteria. The Applicability section explains the scope of the technique, and the presence of techniques for a specific technology does not imply that the technology can be used in all situations to create content that meets WCAG 2.0.


Applies to content using image-based submit buttons.

This technique relates to:


For input elements of type 'image', the alt attribute of the input element is used to provide a functional label. This label indicates the button's function, but does not attempt to describe the image. The label is especially important if there are multiple submit buttons on the page that each lead to different results.

The input element is used to create many kinds of form controls. Although the HTML and XHTML DTDs permits the alt attribute on all of these, it should be used only on image submit buttons. User agent support for this attribute on other types of form controls is not well defined, and other mechanisms are used to label these controls.


Example 1

An input element with an alt attribute

Example Code:

<form action="" method="post">
  <input type="image" name="submit" src="button.gif" alt="Submit" />


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  1. For all input elements that have a type attribute value of "image", check for the presence of an alt attribute.

  2. Check that the alt attribute indicates the button's function.

Expected Results

If this is a sufficient technique for a success criterion, failing this test procedure does not necessarily mean that the success criterion has not been satisfied in some other way, only that this technique has not been successfully implemented and can not be used to claim conformance.