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Creating Accessible Educational Materials

Overview

Images are often added to educational materials to make complex information easier to understand or to simply add visual interest. However, not everyone will be able to see the image (e.g., people with vision impairments, and those who have images turned off to save bandwidth). Also, sometimes images don't load.

Alternative text (alt text) is text added to an image to convey its meaning and purpose of text for anyone who can't see it. Alternative text is:

  • Read aloud to someone using a screen reader.
  • Displayed when an image doesn't load.
  • Indexed by search engines.

Writing Alternative Text

Good alternative text should:

  • Provide an equivalent experience to seeing the image rather than a literal translation of the image. For example, many programs use an image of a floppy disc to indicate a save button. The alt text for this would be "save," not "floppy disc."
  • Be short and to the point.
  • Omit the language "image of" or "picture of."

What should you include when writing alternative text?

  • Does the image contain important text? It should be transcribed, word for word.
  • Is the image a button or a link? The alt text should include what will happen when the image is clicked. For example, the Research Medical Library logo at the top of this page has the alt text "Research Medical Library home" because clicking the image will take you to the library's homepage. There's no need to include "link to" in the text, as a screen reader will automatically include it.
  • Is the image purely decorative? A decorative image is one that adds no additional meaning or context to the page; it is there purely to look nice. If your image is decorative, it should be marked as decorative, rather than having alt text.
  • Is the image complex, like a graph or diagram? The alt text should include a brief description to identify the image. A more detailed description should be written in text elsewhere on the page.

How do you know what to write?

  • Cover up the image or temporarily remove it. Now that's it's gone, what information needs to replace it so that your content still makes sense?

Text in Images

It's best practice not to include text only in images. Text outside of an image can be more easily customized by readers to make it easier to read. For example, someone with dyslexia may change the font to a dyslexia-friendly font, and a person with vision impairment may adjust the size of the font. 

If you do include text in an image:

  • Consider repeating the text near the image. In this case, you don't need to include alt text and can mark the image as decorative.
  • If the text is not repeated elsewhere, the alt text needs to say, word for word, exactly what's in the image.
  • When you're creating the image, make sure there's sufficient contrast between the text and the background it's placed on. Learn more about contrast in text.

How to Add Alt Text to an Image

Microsoft Word and PowerPoint

  1. Right click on the image and select Edit alt text.
  2. A side bar with a text box will open. Enter the alt text or mark the image as decorative.

Adobe Acrobat

  1. Select the accessibility tool.
  2. Select Set alternative text
  3. A text box will open. Enter the alt text or mark the image as decorative.

Canvas and Study

  1. Click on the image and select Image options.
  2. A side bar with a text box will open. Enter the alt text or mark the image as decorative.

Resources