Alternate Text and Decorative Images in PowerPoint

What exactly is alternate text?

Images need accurate descriptions for students who rely on screen readers. Avoid using text-heavy photos and the description should provide enough information within the context of the topic. Keep in mind the context of the picture, which may change the scope of the needed explanation.

Images should never start with a “picture of” or “image of” as the screen reader will identify it as an image. The one exception to this rule is if the context of that information actually matters.

Is this a photography course? Is this an art course? If so, then it might be ok to use “image of” in the description.

How to apply alternate text to an image in PowerPoint Video Overview

Image Context

Image context will change based on the audience and what you want them to learn about the image. The same image could have different descriptions depending on its intent.

Special Notes

Be sure to check all images as sometimes the file name is inserted as the alternate text area. For example, jordison.png might be the default value in the alt text area for an image – be sure to spot-check all images to ensure that the file name did not get inserted.

Keep alternate text less than 100 – 150 characters. If there is more text needed – be sure to include it next to the image on the page. You can also link to a longer description using a separate document!

Want to know more about accessible pie charts and bar graphs?

When do I mark an image decorative?

When images are used that do not convey any meaning and are just for visual effect, it is possible to mark these elements as decorative with the latest versions of PowerPoint. After selecting the image and opening the Alt Text panel, select the checkbox “Mark as decorative”. This has the effect of making the image “invisible” to assistive technologies.

If an image does not include any alternate text information and is not marked as decorative, then assistive technologies may try to read out a file name or will announce the presence of a graphic, but with no additional information. This has the effect of informing the student there might be content, but the student does not have access to that information.

If sufficient information is described through text and images are used, consider marking the graphics as decorative to improve screen reader readability. 

Text Overview of how to apply alternate text to images in PowerPoint?

  1. Right click the image
  2. Select Edit Alt text
Right click the image
Select Edit Alt text.
alternate text in powerpoint

Then, enter a description.

  1. Enter an engaging alternate text description
  2. OR – Mark as decorative
Enter an engaging alternate text description
OR - Mark as decorative
alternate text in powerpoint
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