Klipper can perform actions on the contents of the clipboard, based on whether they match a particular regular expression. For example, any clipboard contents starting with http:// can be passed to Firefox or Konqueror as URLs to open. In addition, if the contents matches a path, similar actions can be performed according to the file's type. e.g., if the path to a PDF file is copied to the clipboard, the file can be viewed in Okular.

To use this feature, just select a URL or path. If there is a matching regular expression in Klipper's list, a menu will appear showing you the programs for your selection. Use the mouse or cursor keys to select a program, and Klipper will run this program, opening the address pointed to by the selection.

If you do not want to perform any actions on the clipboard contents, select Disable This Popup on the pop-up menu to return to what you were doing before. If you leave the menu, it will disappear, leaving you to continue your work. You can change the time that the menu remains for in the settings dialog, with the option Timeout for action popups under the General page. You can separately disable the file path part using the option Enable MIME-based actions under the Actions page.

Actions can be disabled completely by pressing the shortcut Ctrl+Alt+X.

Clipboard contents which match a regular expression can also be edited before performing an action on them. Select Edit contents... at the right of the clipboard entry, and you can change the clipboard contents in the dialog which appears, before clicking the OK button to run the appropriate action.

Pressing Ctrl+Alt+R shows the pop-up menu to repeat the last action which Klipper performed.