Alt text in Canvas: the course images nobody reviews

In Canvas, alt text lives in the image’s Options menu: select the image in the editor, choose Options, and type a description into the Alt Text field. That field starts out filled with the image’s file name, so the first job is replacing it. The editor also has a Decorative Image option and a built-in accessibility checker, both covered below.

Course pages are where a lot of a college’s images quietly pile up: banners, diagrams, pasted screenshots, lecture material saved as pictures. Many are added by instructors and instructional designers, not the marketing team, so they rarely get the review a homepage image does. Students who use screen readers meet both. If you need the case for caring, start with why alt text matters.

Where the field is

Instructure’s guide to managing alt text in the Rich Content Editor says to click the image, click Options, and enter your description in the Alt Text field. It also notes that the field shows the image file name by default. An image nobody touched will therefore be announced as something like this:

Other learning management systems have their own editors and menus. The habit carries over, but check where yours puts the field before you promise a team a shortcut.

What the accessibility checker catches

According to Instructure’s page on the Accessibility Checker in the Rich Content Editor, it flags images with no alt text, alt text that is only a file name, and alt text longer than the recommended fewer than 120 characters. When it finds an issue, you open the checker icon, read the rule in the sidebar, type a fix, and click Apply.

The same page adds a caveat: the file name check is not reliable for files uploaded directly to Canvas. So a clean report does not prove every image is described.

The checker can tell that text exists. It cannot tell whether the text is any good, which is why a quick read-through, ideally by ear, still matters.

When to leave it empty, and when not to

Not every picture needs a description. Canvas offers a Decorative Image option for images that add nothing, and the W3C’s image decision tree says the same: use empty alt text for purely decorative images or ones that repeat nearby text. Our post on decorative versus informative images covers where that line falls.

The flip side is the picture of a slide or flyer. If the words in it appear nowhere else on the page, the W3C tree says the alt text should carry them. For longer material, see alt text in slide decks.

A handoff for the marketing team

Marketing rarely owns the course shell, but it often makes the images that end up in one: program banners, campus photos, infographics. If the description is written when the image is made, the instructor pastes it in instead of inventing it. With SnipAlt, snip the image with Ctrl+Shift+A (⌘⇧A on a Mac) and paste the result into the Alt Text field.

Course sites are also worth including in whatever audit your campus plans around the ADA Title II deadline, and SnipAlt for Colleges describes how teams use it. This is not legal advice; your accessibility office can say what applies to you.