What Cutefish is and whether your Ubuntu system can run it

Cutefish is a desktop environment — the visual layer that sits on top of Ubuntu's core system and lets you click buttons, open windows, and see your files. It is designed to be lightweight and simple, with a clean interface that does not demand much from your computer's processor or memory. If you are running Ubuntu 20.04 or later on a machine with at least 2GB of RAM, you can install it.

Cutefish replaces your current desktop (whether that is GNOME, KDE, or another environment) without removing it. You can switch between them at the login screen after installation. This means you can test Cutefish without losing your existing setup, and switch back if it does not suit you.

The installation itself happens through Ubuntu's package manager, which downloads and installs software from trusted repositories. You will need to open a terminal window and type commands — there is no graphical installer for this step.

Key Takeaways

  • Cutefish is a lightweight desktop environment that works on Ubuntu 20.04 and later, and you can install it without removing your current desktop.
  • The installation requires opening a terminal and running four commands in order: updating your package list, adding the Cutefish repository, installing Cutefish, and logging out.
  • After installation, you log out and select Cutefish from the session menu at the login screen before entering your password.
  • If Cutefish does not work well on your system, you can remove it by running two uninstall commands and return to your original desktop.

Opening the terminal and preparing your system

Press Ctrl + Alt + T on your keyboard. A terminal window will open — this is where you type commands that tell Ubuntu what to do. The terminal shows a prompt (usually ending with a dollar sign or hash mark) where you can start typing.

Before installing Cutefish, you need to update Ubuntu's list of available software. Type this command and press Enter:

sudo apt update

Ubuntu will ask for your password. Type it in (you will not see the letters appear as you type — this is normal for security reasons) and press Enter. The system will then download the latest list of software packages. This step takes a minute or two depending on your internet speed.

The word sudo means "do this as the administrator" — it gives the command permission to make system-wide changes. You will use it for each installation step.

Adding the Cutefish repository and installing the software

Once the update finishes, type this command to add the repository where Cutefish lives:

sudo add-apt-repository ppa:cutefish-ubuntu/cutefish

Press Enter. Ubuntu will ask you to confirm by pressing Enter again. This adds Cutefish's official software source to your system so Ubuntu knows where to find it.

Now update your package list again so Ubuntu knows about the new software from the Cutefish repository:

sudo apt update

Once that finishes, install Cutefish by typing:

sudo apt install cutefish

Press Enter. Ubuntu will show you how much disk space Cutefish needs (usually around 200–300 MB) and ask if you want to continue. Type y and press Enter. The download and installation will take several minutes depending on your internet speed and computer.

When the installation finishes, you will see the prompt return. Do not close the terminal yet — you have one more step.

Logging out and switching to Cutefish at the login screen

Type this command to log out of your current session:

loginctl terminate-session $XDG_SESSION_ID

Press Enter. Your desktop will close and you will see the login screen. You can now close the terminal window if it is still open.

At the login screen, look for a menu or button that shows your current desktop environment — this is usually in the bottom-left corner, the bottom-right corner, or near your username. It might say "Ubuntu" or "GNOME" or the name of whatever desktop you were using before. Click on it.

A list of available desktops will appear. Find Cutefish in the list and click it. Then enter your password and log in. You will now be using the Cutefish desktop.

What to do if Cutefish does not work or you want to switch back

If Cutefish crashes, runs slowly, or you simply prefer your original desktop, you can remove it. Open the terminal again with Ctrl + Alt + T and type:

sudo apt remove cutefish

Press Enter and type y to confirm. Then remove the repository:

sudo add-apt-repository --remove ppa:cutefish-ubuntu/cutefish

Press Enter. Log out and select your original desktop from the login screen menu. Your system will be back to where it started, with no trace of Cutefish.

Removing Cutefish does not affect your files, settings, or any other software. It only takes away the desktop environment itself.

Troubleshooting common installation problems

If you see an error saying "Could not get lock" or "Unable to acquire the dpkg frontend lock", another program is using the package manager. Wait a minute and try the command again. If the problem persists, restart your computer and try once more.

If the Cutefish repository is not found, make sure you typed the repository address exactly as shown: ppa:cutefish-ubuntu/cutefish. Copy and paste it from these instructions if you are unsure. Also check that you are running Ubuntu 20.04 or later — Cutefish does not work on older versions.

If Cutefish installs but does not appear in the login screen menu, try restarting your computer. Sometimes the system needs a full reboot to recognize a newly installed desktop environment.

Frequently Asked Questions

Will installing Cutefish remove my current desktop?

No. Cutefish installs alongside your existing desktop. Both remain on your system, and you choose which one to use at the login screen each time you log in. You can switch back and forth without losing anything.

Can I use Cutefish on Ubuntu 18.04 or earlier?

The Cutefish repository officially supports Ubuntu 20.04 and later. If you are on an older version, you would need to upgrade Ubuntu first. Attempting to install Cutefish on unsupported versions may cause problems.

What if I see a "404 not found" error when adding the repository?

This usually means the repository is temporarily unavailable or the address has changed. Wait a few minutes and try the command again. If the problem continues, check the official Cutefish project page to confirm the correct repository address.

Does Cutefish work on low-end computers?

Cutefish is designed to be lightweight, but performance depends on your specific hardware. If your computer has less than 2GB of RAM or a very old processor, it may run slowly. You can test it without committing — if it does not perform well, the removal process takes just two commands.

Can I customize Cutefish after installation?

Yes. Cutefish has settings for appearance, behavior, and keyboard shortcuts. You will find these in the system settings menu once you are logged into the Cutefish desktop. Changes you make are saved to your user account.