If you have switched from Windows, you know, that you can press Ctrl+Shift+Esc to open task manager and get information about CPU or memory usage or kill unwanted applications. There is no direct equivalent for Linux, but you can use some applications and command-line tools to perform almost all actions that the Windows task manager can do.
In this article I will show you how to perform all task manager related tasks using different applications in Linux. For all examples I will use Ubuntu with the GNOME desktop environment.
Table of Contents
- How to Use Task Manager in Ubuntu
- The Equivalent of Ctrl+Alt+Del
- Creating Task Manager Shortcut
- Wrapping Up
How to Use Task Manager in Ubuntu
Let's start from having a look at applications that provide such functionality in graphical interface.
1. Resources
The application that provides almost fully this functionality is Resources. This application is similar to modern the task manager in Windows 11. Resources is in GNOME Circle so it may come with GNOME by default the future. However at the moment of writing it can be installed from FlatHub using Flatpak:
flatpak install -y flathub net.nokyan.Resources
And then you can run it from the main menu, just type Resources:
Or, use the following command:
flatpak run net.nokyan.Resources
The first tab shows the list of running applications. Here you can see the name of each application and how much memory and CPU time it is using.
To end a specific application, simply select it and then click on the End Application button:
If the application is frozen, click at the arrow next to the End Application button and select Kill Application:
The second tab, Processes, provides more detailed information about running processes, including applications with visible windows and background services. You can view CPU and memory usage per process and sort processes by resource usage. For example, you can click on the Memory, Processor or GPU column to see which processes are using the most RAM, CPU or Video card.
You can also terminate unwanted processes as well as on Applications tab.
The next tab is Processor, where you can check CPU details and view CPU usage chart per core or overall:
Then, there is the Memory tab, where you can see the total amount of RAM and Swap, and their current usage:
Unlike the original Windows task manager, here you can also see GPU usage information on the GPU tab:
And even network transfer speeds for all interfaces:
This application can display a list of running applications instead of processes, like Windows does. This simple feature is very useful for beginners, because dealing with known apps is more easier than trying to find something in a long list of processes most of which you haven't seen and don't even know what they do.
However, this is difficult to implement because there are many window managers in Linux, and each one works differently. Resources uses *.desktop files to determine which apps that have windows are currently running. Therefore, it may not show an application if it does not have a desktop file, or if the executable file specified in it is different from the running process. For example, here you will not see any portable applications installed from ZIP or AppImage if they do not install a *.desktop file in system directories. But it works with applications from Flatpak. Overall it is one of the best task managers for Linux which is like Windows.
2. Mission Center
Mission Center is another application that is very like to task manager in Windows. It is simpler than resources, but here you can check system load and kill unwanted applications. You can install it using Flatpak from Flathub:
flatpak install -y io.missioncenter.MissionCenter
Then an application shortcut will appear in the main menu, or you can launch it using the following command:
flatpak run io.missioncenter.MissionCenter
The app is very minimalistic. The main window contains only two tabs. On the first tab, you can see CPU usage chart and basic system hardware information like CPU caches, the number of cores, and etc:
Also, you can expand additional information about memory, disk, and network usage using the following button:
On the second tab, you can find a list of running applications that were discovered by a program and then a list of processes. The list is sortable by PID, CPU, memory or disk usage:
And, of course, you you can terminate any application or process using the contextual menu:
As you can see, Mission Center recognizes more applications than Resources at the moment of writing. It uses cgroups to determine which applications are running. This is a new systemd standard, and in old systems some applications may not be exposed there.
3. System Monitor
Another popular application that is used as a task manager is System Monitor for GNOME. It comes with GNOME by default. Although, it does not look so interesting as Resources. On the first tab you can see all running processes:
It is not so easy to find the desired process in such a huge list, especially when it is constantly updated. You can use the button with the search icon to filter processes by name:
To kill a specific process, right-click on it and then choose End or Kill:
On the Resources tab, you can see all CPU, memory and network usage. But there is a disadvantage, the information is only collected when this tab is active:
On the third tab, called File Systems you can see the disk space usage:
4. Htop
Two previous applications work in GUI, but the next tool can help you to find out what is happening on your PC in the command line. It has a nice pseudo-graphical interface that shows memory and CPU usage and a list of all processes that are running in your system. You can sort them by PID, user, priority, CPU or memory usage, or even by execution time. To install htop in Ubuntu run the following command:
sudo apt -y install htop
If you need to install htop in Fedora, run:
sudo dnf install htop
After that, you can run the program with the following command:
htop
If you run it in a GUI terminal emulator, you can use the mouse to scroll the process list or perform actions. However, it is also possible to use the tool only with the keyboard only. At the top of the window you can see the CPU usage per core, then the memory and swap usage. On the right side you can see the number of running processes and the system uptime. The rest of the window is filled with the list of processes. You can scroll through them using the up and down arrow keys on your keyboard.
To select the column by which you want to use to sort processes press F6, then use the up/down arrow keys to move the cursor to the desired column and press Enter. You can then use Shift+I to reverse the sort order:
Alternatively, you can simply click on desired column. If you want to find a specific process, press F3 or / and start typing its name:
To stop a process, select it with the arrow keys and press F9. Then select the signal that you want to send to the process. SIGTERM is safe exit and SIGKILL is forced exit without saving data.
The selected process is then terminated. To exit htop, press q or the F10 key. On my opinion it is best task manager for command line in Linux.
5. PS and KILL
Linux has a many other tools, and you can use GNU utilities instead of the tools listed above. Use the free command to check RAM usage:
free -h
Here, look at the Used column.
Free space on the disk can be checked with df:
df -h
You can check how the CPU load has changed by looking at the contents of the /proc/loadavg file:
cat /proc/loadavg
These numbers reflect the average CPU load over 1, 5, and 15 minutes and can help you to determine if the load is increasing or decreasing. If you want to kill a process in terminal, you need to know its PID. This process ID can be found with the ps utility. Just run ps and filter all processes by name using grep, e.g. firefox:
ps aux | grep firefox
The PID is in the second column. The table header will be visible if you run ps without grep. If there are a multiple processes, the lowest PID value usually belongs to the main process that controls the others. Then you can kill that master process using the kill command:
kill -TERM 5439
Or use the -KILL signal if the process is not responding:
kill -KILL 5439
The Equivalent of Ctrl+Alt+Del
In Windows, you can press Ctrl+Alt+Del to launch the task manager running or shut down the PC even if some full-screen application is frozen or consumes a lot of RAM. In Linux you can use Ctrl+Alt+F1...12 to switch to another virtual terminal. These terminals are exist by default in all distributions and one of them is used to run your current graphical environment. Usually this is Ctrl+Alt+F1, Ctrl+Alt+F2 or Ctrl+Alt+F7. All other terminals are empty and you just need to enter your login and password to get to the command line:
From the command line you can restart your graphical environment, for example in GNOME you need to restart GDM:
sudo systemctl restart gdm
When Gnome Display Manager is restarted, it terminates all running applications in the user session, and then displays the login screen.
You can also kill the application that is frozen using command line tools described above. Then, you can simply switch back to your graphical environment using Ctrl+Alt+F1 or ...F2 depending on your distribution.
Creating Task Manager Shortcut
If you want to run any of the applications described above by pressing Ctrl+Shift+Esc, it is very easy to configure. Simply open Settings, then go to Keyboard -> View and Customize Shortcuts -> Custom Shortcuts, and here press the Add Shortcut or Plus button if you already have any shortcuts.
In the next window, fill shortcut name, command path and press the keyboard shortcut you want to use. For example, if you want to add Mission Center it will look like this:
After pressing the Add button, you can press Ctrl+Shift+Esc to launch your task manager.
Wrapping Up
In this article I have shown how to replace task manager in Ubuntu or other Linux distros. As you can see there are plenty of tools that can help you collect information about resource usage and process management. If you know any other great tools for that, please share them in the comments section below.
