Accessibility Checker in canvas

The Rich Content Editor includes an accessibility tool that automatically checks common accessibility errors within the editor and indicates at the bottom right of the indicator if any errors have been detected..This tool can help you design course content while considering accessibility attributes and is located in the Rich Content Editor menu bar. This tool only verifies content created within the Rich Content Editor. 

Learn about using the Accessibility Checker with the Canvas guide How do I use the Accessibility Checker in the Rich Content Editor as an instructor?


Rules used by the Accessibility Checker

All components are designed according to the template set in the institution's Theme Editor and verify the accessibility rules.

  • Table captions: Tables should include a caption describing the contents of the table.
  • Table header scope: Table headers should specify the scope and the appropriate structure.
  • Table header: Tables should include at least one header.
  • 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 on 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.
    • 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.