Accessibility in Canvas - Accessibility checker

Last changed: 06 September 2021

The Rich Content Editor includes an accessibility tool that checks common accessibility errors within the editor.

You can use the Accessibility Checker to design course content while considering accessibility attributes. This tool only verifies content created within the Rich Content Editor. You may use other accessibility tools to verify additional content in Canvas.

All accessibility components retain the parameters set by your institution's Theme Editor template. The Accessibility Checker verifies the following accessibility rules:

  • Adjacent links: Adjacent links with the same URL should be a single link. This rule verifies link errors where the link text may include spaces and break the link into multiple links.
  • Heading paragraphs: Headings should not contain more than 120 characters.
  • Image alt text: Images should include an alt attribute describing the image content.
  • Image alt filename: Image filenames should not be used as the alt attribute describing the image content. Currently, files uploaded directly to Canvas create a redirect that does not properly verify image filenames.
  • Image alt length: Alt attribute text should contain fewer than 120 characters.
  • Large text contrast: Text larger than 18pt (or bold 14pt) should display a minimum contrast ratio of 3:1.
  • Lists: Lists should be formatted as lists.
  • Sequential headings: Heading levels should not be skipped (e.g. H2 to H4). However, the tool does not check if the first header starts with H2 or whether the headings are sequential with the rest of the content in the page. Tables do not begin with H1, which is designated for the page title.
  • Small text contrast: Text smaller than 18pt (or bold 14pt) should display a minimum contrast ratio of 4.5:1.
  • Table captions: Tables should include a caption describing the contents of the table.
  • Table header scope: Table headers should specify scope and the appropriate structure.
  • Table header: Tables should include at least one header.

Note: For text contrast, the Accessibility Checker verifies color using the same calculations as the WebAIM tool and verifies against Theme Editor templates without High Contrast Styles. However, High Contrast Styles must be enabled for verification if a link color is overwritten manually in the Rich Content Editor.

Read more about how to use the Accessibility Checker

 


Contact

IT support helps you with:

  • Support and permissions.
  • New course rooms.
  • Sandbox (a test room where you can try the tools).
  • Create users missing in Canvas and not in Idis.

You reach IT support via extension 6600 or it-stod@slu.se.