Image Alternative Text (Alt Text)

How to Write Good Alt Text

To write good alt text, imagine that you're describing the image to someone over the phone, conveying the point of the image rather than providing a literal description. 

Alt Text Guidelines

• Keep the description short—ideally 125 characters or less—because screen readers will read all the text at once without the navigation options provided with regular page text, which can be navigated by letter or word if desired.
• Be objective (the text alternative should not include information that isn't in the image or commentary about the image).
• Be context-sensitive (describe the point of the image in the context of the page). 
• Add spaces between each letter in an acronym (e.g., A C L U). 
• Do not include the words "image of," figure numbers, textbook page numbers, or page location information in alt text.
• Do not use the same text as the image caption text.
• Leave the alt text empty or mark the image as decorative for decorative images.

How to Add Alt Text to an Image

Use the provided alt-text field in Canvas or Evolution for adding text and use correct punctuation; otherwise, editing directly in code view may break the code.

• Evolution
• Canvas

Evolution

When you insert an image into a page in Evolution, you'll automatically be prompted to enter alt text in the Image Properties window. You can also access this window at any time by right-clicking an image and selecting Image Properties. 

Canvas

Adding alt text in Canvas is similar to the process in Evolution. Either insert an image using the Embed Image button in the Rich Content Editor, or select an existing image, and then select the Image Options button to open the Insert/Edit Image window. Note: In Canvas, the alt text will be the image file name by default. This should always be removed and, when necessary, replaced with descriptive alt text.

If the image is for decorative purposes only and needs no alt text, you can leave the field blank and check the Decorative Image checkbox.

 

Resources

• Alt Text Examples
• Alt Text Decision Tree Links to an external site.: This tool from W3C will help you determine whether you need alt text, a long description, or empty alt text.

Updated September 2025