In Word Online, users can undo and redo one change. Simply click the first icon (Undo) in the Home ribbon, and the change you just made is undone.
The following keyboard shortcuts also can be used:
- Windows, Linux distros, and ChromeOS: Ctrl + Z for undo
- Mac: Ctrl + Z for undo
After undoing a change the redo button will become active. Click the arrow next to the Undo icon (or if you are in the Expanded view, simply click the Redo button). It will be in the list. Click it and the previous change will be reverted to.
After it has been clicked, ReDo will become inactive again.