CHIL Tip: Image Alt Text

Images can enhance learning but only when all students can access the content they convey. UDOIT will flag images without alternative text, which is a crucial component of accessibility. 

Alt text (alternative text) is a short description of an image, read aloud by screen readers. It helps users who are blind or have low vision understand the purpose or content of the image. Users can visit WebAIM article library for more information on the Web Content Accessibility Guidelines (WCAG) on Alt Text

The most frequent places in Canvas where alt text is forgotten are: 

  • Pages 
  • Assignments 
  • Quizzes (descriptions and questions!) 
  • Announcements 

When uploading or editing an image in Canvas, be sure to complete the "Alt Text" field. Write a brief, meaningful description. The description should be specific to the context in which the image is being displayed - think about what information is being conveyed in the picture that the student needs to know. Even though you've added alt text to an image, you will not see it. It’s always available to screen readers, however, via the underlying HTML code of the page.  If the image is decorative and conveys no essential information, mark it as decorative so screen readers can skip it.  

Alt Text Examples

  • Descriptive: "A bar graph showing student growth in reading scores." 
  • Decorative: A fancy swish or border to start a new section of the page that doesn’t add content

Impact Population

  • Users relying on a screen reader to read the content of a web page
  • Users who have a network connection issue causing images to fail to load
  • <Archaic> Users who browse the web with images turned off by default for faster loading

Summary 

  • All meaningful images need alt text 

  • Use concise, clear descriptions 

  • Mark decorative images appropriately 

Additional Resources 

  • ASU EdPlus Image Accessibility Creator AI Tool  - Designed to effortlessly generate alt text and detailed descriptions, as well as extract text from slides and images that are not accessible. Just upload your image and hit 'Create Image Details.'