What is the shortcut key to "undo" last action on a Microsoft word page?

Word processing software provides keyboard shortcuts as quick alternatives to using the mouse for common commands. Each shortcut is a fixed combination of keys assigned to one specific action, and these combinations are consistent across most Microsoft Office applications.

The shortcut that reverses, or "undoes", the most recent action performed in Microsoft Word is Ctrl + Z. Pressing it repeatedly continues stepping backward through the history of recent edits, one action at a time.

Ctrl + A selects all the text in the document, Ctrl + X cuts the selected text, removing it and copying it to the clipboard, and Ctrl + U applies or removes underline formatting on selected text. None of these three reverse a previous action, so none of them can be the undo command.

It helps to remember Ctrl + Z alongside its opposite, Ctrl + Y, which redoes an action that was just undone.