Exceljet

Quick, clean, and to the point

Check and uncheck box

Windows shortcut 
Space
Mac shortcut 
Space

This shortcut will check and uncheck checkboxes in a dialog box. First select the checkbox using tab or shift tab.

Related videos

The videos below demonstrate this shortcut.
In this video, we'll look at some tips and shortcuts you can use to control dialog boxes using only the keyboard.
How to use your keyboard to navigate dialog boxes in Excel for the Mac