How to set default applications in Kubuntu (KDE)

Kubuntu uses the KDE Plasma environment to manage application preferences, file associations, and system-wide defaults. Configuring default applications ensures that specific file types or links always open with the desired tools. This approach offers better consistency when working with various file formats and protocols.

KDE Plasma organizes default application settings under a dedicated System Settings panel. The Default Applications module handles categories such as web browsers, email clients, terminal emulators, and file managers. Choosing preferred programs in these sections updates internal references so that file operations and URI actions launch with the selected tools.

Underlying configuration files track the relevant mime types and user-specific preferences. KDE Plasma synchronizes these selections upon saving any changes, avoiding manual edits to text-based configuration. This graphical interface provides immediate effect, simplifying the process of choosing or adjusting defaults across the environment.

1. Open System Settings from the Application Launcher.
2. Select Applications in the left sidebar.
3. Click Default Applications to view configurable categories.
4. Choose a category, such as Web Browser, from the list.
5. Select the desired application from the dropdown list.
6. Repeat the selection process for other categories like Email Client or File Manager.
7. Click Apply to confirm changes.
8. Test the new defaults by opening relevant file types or links.

   Consider installing additional software if the preferred default application is unavailable.