The universal keyboard shortcut to undo on keyboard is Ctrl+Z on Windows and Command+Z on Mac. Pressing this shortcut once reverses your last action, and pressing it repeatedly undoes multiple previous actions in reverse chronological order.
How to undo on keyboard: the universal shortcuts
The fastest way to correct a mistake is to use the undo keyboard shortcut. On Windows, hold the Ctrl key and press Z. On Mac, hold the Command key and press Z. Each press steps back one action, so you can undo a series of changes by pressing the shortcut multiple times. This works across virtually all applications, from word processors to image editors to web browsers.
How to redo on keyboard
If you undo an action and then decide you want it back, use the redo shortcut. On Windows, press Ctrl+Y or F4. On Mac, press Command+Shift+Z. Redo reverses the last undo, restoring the action you removed. You can also press these shortcuts repeatedly to redo multiple undone steps.
Undo limits in Microsoft Office and Google Docs
In Microsoft Word, PowerPoint, and Excel, the default undo limit is typically 100 actions. This means you can step back through up to 100 of your most recent changes. However, some actions cannot be undone at all, such as selecting commands on the File tab or saving a file. In Google Docs, Ctrl+Z (Windows and Chrome OS) or Command+Z (Mac) undoes the last action, and all changes are automatically saved to Google Drive. This means every undo is also saved, so you cannot revert past a save point as you might in a local file.
Customizing the undo limit in Microsoft Office
If the default 100-action limit is not enough, you can customize the undo limit in Microsoft Office applications on Windows by modifying the Windows Registry. Specifically, you add a DWORD (32-bit) Value named "UndoHistory" in the relevant Office application's Options registry path. Before doing this, be aware that increasing the undo limit requires more RAM and can negatively affect application performance. A larger undo history means the application must store more states in memory, which can slow down your work, especially on systems with limited resources.
