Alternatively referred to as Control 0 and C-0, Ctrl+0 is a shortcut key most often used to reset back to the default zoom level.
How to use the Ctrl+0 shortcut key
The "0" used with this shortcut is the "0" at the top of the keyboard and not on the numeric keypad.
Ctrl+0 in Excel and other spreadsheet programs
Ctrl+0 in Microsoft Word
Toggles 6pts of spacing above the paragraph.
Using Ctrl+0 in an Internet browser
With all major Internet browsers (e.g., Chrome, Edge, Firefox), pressing Ctrl+0 resets the font size to the default size. If you've used the Ctrl++ (plus) to zoom in or Ctrl+- (minus) to zoom out, this shortcut resets the browser back to the default font size.
Related keyboard shortcuts
Below are links to related keyboard key and keyboard shortcut pages.