Offensive Security Researcher & Quantum Cryptography Analyst

How to Set Up KDE Plasma in Ubuntu: Complete Installation and Customization Guide

Abdul Wahab Junaid
How to setup KDE Plasma in ubuntu

I switched a personal workstation from GNOME to KDE Plasma somewhat by accident — an upgrade left GNOME in a rough state, and rather than spend an evening fixing it, I figured I’d finally try Plasma properly instead. I ended up staying. The customization depth is genuinely a different category from GNOME’s more opinionated, locked-down approach, and for anyone who likes tweaking exactly how their desktop looks and behaves without fighting the defaults, it’s worth the switch. This guide covers installing KDE Plasma on Ubuntu from scratch, choosing the right package for how much of the KDE ecosystem you actually want, the display manager decision, and how to configure and troubleshoot it afterward.

What KDE Plasma Is

KDE Plasma is a desktop environment built on the Qt toolkit, known for deep customizability — theming, widgets, “Activities” (a distinct concept from simple virtual desktops, letting you group entirely different sets of running apps and layouts for different contexts), and a highly configurable panel/taskbar system. Ubuntu’s official KDE-based flavor is called Kubuntu, but you don’t need to install a separate distribution to get Plasma — it installs cleanly as an additional desktop environment on top of standard Ubuntu.

Before You Start

As with any large package install, update first:

sudo apt update
sudo apt upgrade -y

Choosing the Right Package: Three Options, Three Footprints

This is the decision that matters most, and it’s where I see people over-install without realizing it. There are three meaningfully different packages, and picking the right one for your actual needs saves both disk space and install time.

Option 1: kubuntu-desktop (Full Kubuntu Experience)

sudo apt install kubuntu-desktop -y

This installs the complete, official Kubuntu desktop bundle: Plasma itself, plus the full suite of KDE applications (Dolphin file manager, Konsole terminal, KDE’s office and multimedia apps, and Kubuntu-specific theming and branding). This is the largest of the three options — expect well over a gigabyte of downloads and multiple gigabytes of disk space once installed.

Option 2: kde-plasma-desktop (Plasma Shell Only)

sudo apt install kde-plasma-desktop -y

This is the option I actually recommend for most people adding Plasma to an existing Ubuntu install: it gives you the core Plasma shell, KWin window manager, and essential components, without pulling in the entire KDE application suite. You keep your existing GNOME/GTK applications (Firefox, whatever else you already have) and just get a different desktop shell around them. It’s noticeably lighter and faster to install than the full kubuntu-desktop bundle.

Option 3: kde-standard (A Middle Ground)

sudo apt install kde-standard -y

This sits between the two — the core Plasma shell plus the applications most Plasma users actually expect day-to-day (without the absolute entirety of KDE’s application catalog that kubuntu-desktop pulls in). It’s a reasonable choice if you want a genuinely usable KDE experience out of the box without either the bare-minimum shell or the maximalist full Kubuntu bundle.

My personal recommendation: start with kde-plasma-desktop for the leanest install, and add specific KDE applications individually later (sudo apt install dolphin konsole kate, for example) as you discover you actually want them, rather than installing everything up front.

The Display Manager Decision

This is the part that catches people off guard mid-install. Ubuntu defaults to GDM3 (GNOME’s display manager). KDE’s native display manager is SDDM (Simple Desktop Display Manager), which offers better visual integration with Plasma and native support for Plasma’s Wayland session.

During installation, you’ll typically be prompted to choose which display manager should become the system default. Your options, practically speaking:

I generally recommend choosing SDDM if Plasma is going to be your primary or exclusive desktop environment going forward, and keeping GDM3 if you’re installing Plasma alongside GNOME and expect to switch between the two regularly — either display manager can launch either desktop environment; the choice is really about which one’s login screen and session-switching behavior you prefer.

If you need to change this decision after the fact:

sudo dpkg-reconfigure sddm

Or, to reconfigure whichever display manager package is currently installed generically:

sudo dpkg-reconfigure gdm3

Reboot and Log In

sudo reboot

At the login screen, look for a session-selector icon (usually near the password field or in a corner of the screen) and choose “Plasma” (or “Plasma (X11)” / “Plasma (Wayland)” if both are offered) before entering your credentials.

Plasma Version and Ubuntu LTS Alignment

Worth knowing precisely because it affects what features are available: Ubuntu 24.04 LTS ships with KDE Plasma 5 in its default repositories, matching that release’s package base — even though Plasma 6 exists upstream and is genuinely a significant release with a Wayland-first focus. If you specifically need Plasma 6 features, you’d need either a newer Ubuntu release that packages it by default, or the Kubuntu Backports PPA (covered below), rather than expecting it from the default 24.04 repos.

Getting Newer Plasma Versions via the Backports PPA

For point releases and incremental updates within the Plasma version your Ubuntu release ships, Canonical/Kubuntu maintains a backports PPA that delivers updates faster than waiting for the next Ubuntu LTS:

sudo add-apt-repository ppa:kubuntu-ppa/backports
sudo apt update
sudo apt full-upgrade -y

I’d flag one thing about PPAs generally: they’re maintained outside Ubuntu’s own QA process, so while the Kubuntu backports PPA is a well-established and reputable one specifically for KDE updates, it’s still worth understanding you’re opting into a faster, less-tested update cadence than the stock LTS repositories provide.

Post-Install: Basic Plasma Customization

A few of the first things I configure on a fresh Plasma install:

System Settings is the equivalent of GNOME’s Settings app — accessible from the application launcher (usually bottom-left) or by right-clicking the desktop. This is where themes, panel layout, workspace behavior, and virtually everything else lives.

Widgets can be added directly to the desktop or panel by right-clicking and choosing “Add Widgets” — Plasma’s widget system is considerably more flexible than GNOME’s extension-based approach, letting you drag, resize, and reposition elements freely rather than working within a fixed layout.

Activities vs. Virtual Desktops — this distinction is genuinely unique to KDE and worth understanding early: virtual desktops are just separate workspaces for the same set of windows/apps (similar to GNOME’s workspaces), while Activities let you define entirely separate contexts — different wallpapers, different running applications, different widget layouts — that you switch between as a whole. I use Activities to separate “work” and “personal” contexts on the same machine, something GNOME’s plain workspace model doesn’t really offer.

Managing KDE Applications Selectively

Since I recommended starting lean with kde-plasma-desktop, here are the applications I typically add back individually rather than accepting the full kubuntu-desktop bundle:

sudo apt install dolphin -y     # file manager
sudo apt install konsole -y     # terminal emulator
sudo apt install kate -y        # text editor
sudo apt install spectacle -y   # screenshot tool
sudo apt install ark -y         # archive manager

This lets me build up exactly the KDE application set I want, rather than carrying the weight of applications I’ll never open.

Removing KDE Plasma Cleanly

If you want to remove KDE and revert fully to GNOME:

sudo apt purge kubuntu-desktop kde-plasma-desktop kde-standard -y
sudo apt purge 'kde-*' 'plasma-*' -y
sudo apt autoremove --purge -y

Note the quoting around the wildcard patterns ('kde-*', 'plasma-*') — this prevents the shell from attempting to glob-expand them against local files before passing them to apt, letting apt itself interpret the wildcard against package names instead. This matters exactly the way it does for any command receiving a glob pattern meant for the program to interpret rather than the shell.

After purging, restore GDM3 as the default display manager if you’d switched to SDDM:

sudo apt install gdm3 -y
sudo dpkg-reconfigure gdm3
sudo apt purge sddm -y
sudo apt autoremove --purge -y
sudo reboot

Running Both GNOME and KDE Side by Side

This is fully supported and something I’ve done on and off for months at a time — both desktop environments coexist fine on the same system, since they’re just different session options presented at the same login screen. The main things to watch for:

Troubleshooting

Login screen shows a black screen or crashes back to the login prompt after selecting Plasma: Try the alternate session type first — if “Plasma (Wayland)” fails, attempt “Plasma (X11)” instead, since Wayland compatibility issues (particularly with older or proprietary GPU drivers) are a common cause of this specific failure mode. Check logs with journalctl --user -b -1 for detail on the previous failed session.

Fonts or icons look wrong/missing after install: Reinstall the Breeze icon theme and standard fonts:

sudo apt install --reinstall breeze-icon-theme fonts-noto -y

GTK applications look visually inconsistent inside a Plasma session: Install the GTK theming bridge so GTK apps respect Plasma’s active theme rather than falling back to a default GTK look:

sudo apt install kde-config-gtk-style -y

Then set it from System Settings → Appearance → Application Style → GNOME/GTK Application Style.

Package conflicts between GDM3 and SDDM during install: This happens when apt can’t cleanly decide which display manager should own the login. Explicitly reconfigure after install completes: sudo dpkg-reconfigure sddm (or gdm3), rather than letting the installer’s default choice stand if it seems inconsistent.

Performance Notes

KDE Plasma has a reputation — largely accurate in my experience — for being lighter on system resources at idle than GNOME, particularly the more minimal kde-plasma-desktop install without the full application suite layered on top. If you’re setting this up on an older machine or a resource-constrained VM specifically because GNOME felt sluggish, Plasma (especially with animations/effects trimmed back in System Settings → Workspace Behavior) is a reasonable next thing to try before dropping all the way down to something like XFCE or LXQt.

Security Considerations

The same general caution from the GNOME setup guide applies equally here: installing a full desktop environment on a server meaningfully expands the package count, running services, and overall attack surface compared to a headless install. If Plasma is genuinely temporary (a one-off GUI need, evaluating the desktop environment, running a graphical installer), plan to remove it afterward using the purge steps above rather than leaving an unused full desktop stack installed indefinitely on a production system.

Compatibility Notes

This guide reflects Ubuntu 24.04 LTS, which packages KDE Plasma 5 by default; Plasma 6 requires either a newer Ubuntu release or the Kubuntu backports PPA as covered above. Package names (kubuntu-desktop, kde-plasma-desktop, kde-standard, sddm) have been consistent across recent Ubuntu LTS releases (22.04, 24.04). On Debian directly (rather than Ubuntu), the equivalent packages are largely the same (kde-plasma-desktop, task-kde-desktop via tasksel), though without Kubuntu’s specific branding and default-application curation.

Summary

KDE Plasma installs on Ubuntu through one of three metapackages depending on how much of the KDE application ecosystem you want alongside the desktop shell itself — kubuntu-desktop for the full official Kubuntu experience, kde-plasma-desktop for a lean shell-only install (my usual recommendation), or kde-standard as a middle ground. The main decision point during install is your display manager — SDDM for the most native Plasma-themed login experience, or keeping GDM3 if you’re running Plasma alongside GNOME and want to switch between the two. Both desktop environments coexist cleanly on the same system, and either can be removed cleanly afterward with apt purge and autoremove --purge if you decide it’s not for you.

References

Exit mobile version