You should use alt text in Word if your documents will be read by people who rely on accessibility tools like screen readers. And once you add alt text in Word, you can view or edit it at any time.

To add your own alt text to a photo or video, upload the photo, mouse over it and click Edit, and then select Alternative Text on the left side. To edit it, select Override Generated Alt Text ...

To add alt text to images in PowerPoint, or edit an image's existing alt text, select the photo and choose "Edit Alt Text…" from the Picture Format toolbar. When you add an image to PowerPoint ...

This post shows how to add Alt Text to Images, Charts, Objects & PivotTables in Excel. Alt Text provides useful information to persons with disabilities.