Images need alternative text in PDFs, just like they do in Word and HTML documents. If you added alternative text for an image in the “description” box in Word, then that text will carry over when you save the document as a PDF. However, you can add, edit, and remove alt text in Acrobat.
Edit Alt Text with the “Set Alternate Text” Tool
A quick way to check and fix your images in Acrobat is to click “Set Alternate Text” under “Accessibility” tools. A small window will open that will let you click through your images and add alt text where needed. Check the “Decorative figure” box to silence images that would add nothing meaningful for someone using a screen reader.
Edit Alt Text with the “Touch Up Reading Order” Tool
When you use the “Touch Up Reading Order” tool, each image should be marked as a “Figure.” In a black box at the top of the figure, you will either see that image’s alternative text, or a message saying “No alternative text exists.” Right click on a figure and choose “Edit Alternate Text” to add or change alt text.
Make “Decorative” Images Silent
Sometimes, the alternative text for an image would contribute nothing to your message beyond what’s already in the text. Rather than be redundant, you can silence the image so screen reader users won’t have to listen to redundant text.
- Click the “Touch Up Reading Order” tool.
- Click the “Figure” tag in the top left corner of the image to select that image.
- On the “Touch Up Reading Order” tool, click “Background.”
- You will no longer see a gray box around the image. The picture will still be visible, but won’t be spoken by screen readers.
Video on Adding Alternative Text to PDFs
The following link will display a video that shows an older version of Acrobat. Although the old version looks a little different from the current version, the video does a pretty good job of illustrating the basic process. Unfortunately, it lacks the “Set Alternate Text” tool. (To view the video full screen, right click it after it starts playing. Then choose “Full Screen.”)