When adding important or informative graphical images into documents, you must include descriptive text (alt text) with the images. Assistive technology like screen readers can read these descriptions to blind and low-vision users.

There are several types of graphics that may appear in reports and other documents:

Decorative images

Decorative images do not have a purpose outside of decoration and do not need descriptive alt text. Authors should instead manually set these types of images as decorative so that screen readers will skip over them.

Informational graphics

If an image contributes important information to the document, authors must include a brief alt text description of this type of image. Start with the key parts and keep the alt text brief. If the image is important enough to require a longer description, include the longer description in the body of the document, not in the alt text.

Complex images

This includes more complex graphics such as images of graphs and charts. It may even include complex mathematical equations, chemical formulas, or other STEM content. The National Center for Accessible Media (NCAM) has developed a complex image guide for authors who need to describe this type of content. Visit the NCAM Image Description Resources page for more information. Remember that long descriptions of images belong in the body text of the document, not in the alt text field. Alt text is for brief descriptions only.

Who is responsible for non-text content?

The writer of the report who selected the image may be the best person to write the alt text for that image. This is because the writer can best explain the importance of the image in the report.

How to include alt text in different document types

Microsoft Word and PowerPoint

Right click on the image. Type the alt text in the alt text field. If the image is decorative, check the box on the sidebar to mark it as decorative.

Microsoft Excel

Avoid using images in Excel unless it is absolutely necessary. Images cannot be embedded into Excel sheets, so they are invisible to screen readers.

If you must use multiple images in Excel, consider attaching a list of them with brief descriptions of each one.

Another option is to enter a description inside a cell that is near the non-text element.

PDF

Alt text will transfer from Microsoft 365 documents into the Adobe PDF format. You can also add alt text to an image using the Accessibility toolbar. When you run the Accessibility Check, Adobe automatically notifies you about figures that need alt text. By right clicking on the images list, users can select to add alt text.

Google Docs

Right click on the image and choose alt text from the menu. A sidebar will appear with a Description field where you can enter an alt text description.

There are a couple of things to know about Google Docs alt text:

• There is no way to mark an image as decorative. Therefore, if you download a document as a Word file, make sure to use Microsoft Word to mark any decorative images.
• If you download your Google Doc as a Word document, any descriptive alt text should still be there.