Alternatively referred to as Control+D and C-d, Ctrl+D is a keyboard shortcut that varies depending on the program. For example, in most Internet browsers, it is used to add the current site to a bookmark or favorite. But, other programs, like Microsoft PowerPoint, use it to duplicate objects.
How to use the Ctrl+D keyboard shortcut
Ctrl+D in an Internet browser
All major Internet browsers (e.g., Chrome, Edge, Firefox, Opera) pressing Ctrl+D creates a new bookmark or favorite for the current page. For example, you could press Ctrl+D now to bookmark this page.
Ctrl+D in Excel and Google Sheets
In Microsoft Excel and Google Sheets, pressing Ctrl+D fills and overwrites a cell(s) with the contents of the cell above it in a column. To fill the entire column with the contents of the upper cell, press Ctrl+Shift+Down to select all cells below, and then press Ctrl+D.
Using the Ctrl+R shortcut will fill a row cell(s) instead of a column.
Ctrl+D in Microsoft PowerPoint
In Microsoft PowerPoint, the Ctrl+D keyboard shortcut inserts a duplicate of the selected slide. Select the desired slide in the thumbnail pane on the left side of the PowerPoint program window, then press the Ctrl+D keyboard shortcut. This keyboard shortcut may also be used to duplicate objects like shapes.
Ctrl+D in Microsoft Word
Ctrl+D in the Linux shell
In the Linux command-line shell, pressing Ctrl+D logs out of the interface. If you used the sudo command to execute commands as another user, pressing Ctrl+D exits out of that other user and puts you back as the user you originally logged into.
Related keyboard shortcuts and keys
Below are links to related keyboard shortcuts and individual key pages.