Alternative Text in Canvas

Alternative text, referred to as alt text, is a written description of an image that provides context for users unable to see it. Alt text supports students whether they have vision challenges and use a screen reader, or their device is unable to load images due to a tech issue. Instructors must evaluate if an image offers additional instructional value to the surrounding text and, if so, write a short description in the Image Options inside Canvas. For images that are purely decoration, Canvas also offers a way to mark as decorative. This guide explains writing alt text for your Canvas course images:

Add context: Edit common numbering used in generic files names, such as 143228942.jpeg to a meaningful description.
Be specific: Relate the description to the intended message of the imagery - grey rock measuring 1.5 inches rather than grey rock next to a ruler.
Keep it concise: Describe the image clearly and concisely in 1-3 sentences or around 125 characters.
Avoid redundancy: No need to repeat information provided in the surrounding text.
Determine if decorative: If redundant to the text, or only used to beautify your content, mark the image as decorative.

Add Alt Text During RCE Upload

Step 1: Upload an Image

From anywhere in Canvas offering the rich content editor, select Images represented with a picture icon.
Click Upload Image.

Step 2: Enter Alt Text or Mark Decorative

Once you've selected an image, type your meaningful description in the Attributes option for Alt Text.
If your image is only for decoration or the text already explains the information shown in the image, check the box for Decorative Image.
Remember, not to use generic file names and numbers for alt text.
Click Submit to save your work.

Upload to Files Feature

If staying organized is important to you, uploading images in the Files feature allows you to upload to different folders.

To upload in Files, open Files on the course navigation menu, then either click the Upload button to select an image or drop the file into the upload space.
Note, images uploaded straight to Files can be marked decorative unless the Files feature is shared directly with students in the course navigation menu.
Once you add the image to a place in your course seen by students, you must enter appropriate alt text.
Images uploaded with the rich content editor are saved in an Uploaded Media folder located in Files.

Add or Edit Alt Text After Upload

You can easily add or edit the alt text of any image in Canvas or mark it decorative.

Select the image to display the Image Options button.
Click the Image Options button to open a slide out tray.
Be sure to click Done to save any changes.

Alt Text in Canvas Video

00:07: How do I manage alt text and display options for images embedded in the rich content 00:11: editor? 00:13: Open the rich content editor when using one of the canvas features, which support the editor. 00:19: Click the image then click the options link. 00:22: You can manage display options for embedded images in the image options menu. 00:28: If an image is added to the rich content editor via URL the image 00:32: options menu includes the file URL field. 00:35: The URL can be updated to change the image displayed in the editor. 00:40: Enter an alternative text description or text tags in the alt text field. 00:45: By default the alt text field displays the image file name. 00:49: Alt text is read by screen readers and it displays when an embedded image 00:53: cannot display. If the image is decorative and does not require, alt 00:57: text select the decorative image option. 01:02: By default the embed image display option is selected for embedded images. 01:07: To display the image file link select the display text link display option 01:11: the file link will replace the image in the rich content editor. 01:17: Click the size drop-down menu. You can select a small medium 01:21: large or extra-large image size or you can select to enter 01:25: custom dimensions. 01:28: To customize the size of your image enter the custom height or width dimension 01:32: in one of the two Dimension fields. As you enter a value in one 01:36: field the other fields value changes in order to retain the image aspect 01:40: ratio. 01:43: You can also manually adjust the image size in the rich content editor. 01:47: When you click the image adjustment handles appear in each corner. 01:51: Click and drag the handles to adjust the image size. 01:55: If you select a custom image size, you can change the size selecting the pixels 01:59: Dimension type radio button and changing one of the two Dimension type fields. 02:05: You can also change the custom image size by selecting the percentage Dimension type 02:09: radio button and changing the percentage field. 02:13: Click the done button. 02:16: View the image embedded in the rich content editor. 02:19: This guide covered how to manage alt text and display options for images embedded 02:23: in the rich content editor.

Alt Text in Canvas FAQ

Do I need to add alt text if the image has words on it?

Yes, images with text on them must include alternative text so that Canvas and screen readers properly share the information with students. An exception is when the image is repeating text in the content, making it repetitive - in this case, the image is then marked decorative.

Why is my Ally Accessibility Report low and indicating I need to add alt text to images in Files?

Your accessibility score is negatively impacted if image files are not marked decorative or given alt text in Files since this feature can be made available to students. While you can use a single image file in multiple places, alt text is uniquely managed in each place you view the image. This means you can mark images as decorative in Files to raise your Ally score, while writing alt text for the same image in other parts of your course.

Do I need to add alt text to an image I use more than once?

Yes, as the use of an image can change depending on where it's used within a course and instructors need to adjust the alt text to represent different context. You must add alt text to an image each time you use it as alt text doesn't get saved to the image file.