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9. Images

Requirement

Alternative text is provided for all informative images and appropriately describes the content and/or purpose of the image.

Evaluation Process

Images are required to have an ALT attribute (or title for SVG images). Images that lack this attribute will be flagged as part of the 1. Automated Test criteria, but it is important to note that the automated test will only evaluate if the attribute is present, not if it is appropriate. The appropriate ALT attribute for an image depends on purpose or function of the image, which can fall into three categories: 

  • Informative: These are images that provide meaningful information. This can include pictures that are relevant to the content, charts, or graphs. These images must include ALT text that accurately describes the purpose of the image.
  • Decorative: These are images that provide visual effects (i.e., "eye candy") and do not provide meaningful information. These may be used for decorative or layout purposes. For standard images, use alt="". For SVG images, use aria-hidden="true".
  • Functional: These are images that function as a link or other interactive element. The ALT text description should include the purpose of the image, not a description of that image. For example, an link with an image of a house that returns the user to the home page, would have a description of alt="Return to home page".

To examine the ALT text of an image, right-click on the image and choose "inspect." Alternatively, use a tool, such as the Web Developer Toolbar or ANDI to expose the ALT text on a page. 

Three images with their ALT text exposed.
Using the Web Developer Toolbar, you can expose the ALT text of the images on the page so that reviewing images is easier than looking at the source code.

Scoring Guide

  • Pass: All informative images have an appropriate ALT text. All functional images describe the purpose of the function. All decorative images are marked appropriately.
  • Partial Fail: A few informative images lack appropriate ALT text and/or some decorative images have ALT text that should be removed.
  • Fail: Images lack the ALT attribute entirely. Functional images lack the appropriate ALT text. More than a few informative images lack ALT text.
  • Not Applicable: There are no images on the website.
  • Unknown: No images were found during testing, but it is possible there might be some outside the scope of the testing. 

More Information

Relevant WCAG Information

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