Alt Text and Long Descriptions

What are alt text and long descriptions?

Alt text and long descriptions are text descriptions of images which can be read by screen readers.

Who uses alt text and long descriptions?

• Students who are blind or have low vision.
• Students who have various cognitive and reading disabilities.
• Neurodivergent students.

What’s the difference between alt text and long descriptions?

Alt Text

• Alternative text is a text substitute for non-text content.
• Short, approximately 120-character description of an image.
• The goal is to capture the contextual essence of an image or graphic.
• In addition to supporting screen reader users, it is also the text that is displayed when an image fails to load. 

Long Descriptions

• Long descriptions are text substitutes that require more than 120 characters.
• In science, graphs, charts, and other complex images often require more detailed information for student comprehension, particularly when the images are used for assignments and assessments.
• The goal of long descriptions is to focus on the crucial elements that students need to know to successfully, omitting unnecessary details. 

For Example…

A helpful metaphor for this might be to think of the alt text as the description of an item on a menu. It is short, but contains enough information for you to understand the dish. 

• Example: A fish taco with salsa, crema, and cabbage slaw.

The long description is how you would describe the dish to a friend who has never eaten that item. You would want to provide enough relevant information and answer any questions your friend might have about the dish.

• Example: A fish taco containing a battered and fried piece of cod on top of a corn tortilla. The taco is topped with a shredded cabbage slaw and a salsa roja. The salsa contains tomatoes, onions, and jalapeño, with crema drizzled on top.

Resources

Alt Text: Whose Responsibility Is It?
Alt Text and Long Descriptions: A Practical Guide
Alt Text: Canvas Best Practices (coming soon)