How to Clean Up Flatpak Files on Linux

What Causes This?

Flatpak apps store shared runtimes, old app versions, and cached download files so programs can run consistently across Linux systems. Over time, these files can pile up after app updates, removals, or runtime changes, especially if unused dependencies are not cleaned automatically. The result is wasted disk space and a cluttered Flatpak installation.

Common Symptoms

• Disk space keeps shrinking even after uninstalling Flatpak apps
• flatpak list shows runtimes you do not recognize or no longer need
• The .var or Flatpak storage folders are using several GB of space
• Software updates feel slower because old Flatpak data is still present
• You see multiple old runtime versions installed side by side

How to Fix It Manually

1. Open a terminal

   • On most Linux systems, press Ctrl+Alt+T.
   • You can also open your app menu and search for Terminal.

2. Check what Flatpak has installed

   • Run:

     flatpak list

   • This shows installed apps and runtimes.
   • If you want to see only runtimes, run:

     flatpak list --runtime

3. Remove unused runtimes and old dependencies

   • Run:

     flatpak uninstall --unused

   • Flatpak will identify runtimes and related packages that are no longer needed by any installed app.
   • Review the list carefully, then confirm the removal.

4. Clear cached Flatpak downloads

   • Flatpak may keep downloaded files in its cache.
   • Remove them with:

     rm -rf ~/.cache/flatpak/*

   • If you use system-wide Flatpak installs, you may also need to clear root-owned cache folders depending on your distro.

5. Check app-specific data in the user folder

   • Flatpak apps often store per-app data in:

     ~/.var/app

   • List the folders:

     ls ~/.var/app

   • If you already removed an app but its data folder is still there, you can delete that specific leftover folder manually:

     rm -rf ~/.var/app/app.id.here

   • Only remove folders for apps you are sure are no longer installed.

6. Remove old disabled runtimes if they still remain

   • Show all installed refs, including versions:

     flatpak list --all

   • If you spot an old runtime version you no longer need, remove it with:

     flatpak uninstall runtime/name/version

   • If you are unsure, stick with flatpak uninstall --unused, which is the safer option.

7. Verify the cleanup

   • Run:

     flatpak list

     and

     du -sh ~/.var/app ~/.cache/flatpak 2>/dev/null

   • This helps confirm that unused files and cache data have been removed.

Fix It Automatically with Kudu

If you do not want to inspect Flatpak runtimes, cache folders, and leftover app data by hand, Kudu can scan your system and identify safe cleanup opportunities automatically. It helps remove unnecessary files without the guesswork, which is especially useful if storage keeps disappearing and you are not sure where Flatpak is keeping old data.

Download Kudu Free →