Some Linux apps go full screen when you press F11 — browsers do it, Ghostwriter does it, most “proper” desktop applications do it. But F11 is merely a convention that each app implements for itself, and plenty of apps never bother. I ran into this with the Claude Desktop RPM wrapper (an Electron app): F11 does precisely nothing.
The good news: on KDE Plasma, full screen isn’t only the app’s job. KWin — Plasma’s window manager — can force any window into full screen from the outside, whether the app cooperates or not. Here are three ways to do it, in ascending order of permanence.
The always-works menu: Alt+F3
With the stubborn window focused, press Alt+F3 to open KWin’s window operations menu, then choose More Actions → Full Screen. This works on literally any window on your system — no app cooperation required.
Two notes on this:
- On a MacBook keyboard (I’m on a MacBook Pro running Fedora KDE, and presumably the Air behaves the same), the function keys default to their media roles, so the actual combination is Fn+Alt+F3. It works beautifully.
- The same menu is your escape hatch: Alt+F3 still works when the titlebar is gone, so you can toggle full screen back off the same way. Worth remembering before you make a window swallow the screen.
The Alt+F3 menu is one of KDE’s best-kept secrets in general — it’s the “there’s always a way in” door for any misbehaving window. Always-on-top, moving a window that opened off-screen, sending it to another desktop: it’s all in there.
The proper fix: bind “Make Window Fullscreen”
KWin ships a dedicated Make Window Fullscreen action — but it comes unbound by default, which is why nobody discovers it.
- Open System Settings → Keyboard → Shortcuts
- Search for “fullscreen” under the KWin section
- Assign a shortcut — I’d suggest Meta+F11
Now you have a universal full screen toggle that works on every window on the machine, including Electron wrappers that never wired up F11 themselves. One shortcut, fleet-wide behaviour: it works identically on a Notion PWA, novelWriter, a terminal, anything.
The automatic route: Window Rules
If you always want a particular app full screen, a KWin Window Rule can enforce it at launch:
- System Settings → Window Management → Window Rules → Add New
- Match on the app’s window class (the “Detect Window Properties” button lets you click the target window instead of guessing)
- Set Fullscreen to Apply initially
Overkill for everyday apps, but handy for kiosk-style setups or a dedicated writing machine.
Maximized vs. full screen — know the difference
While you’re in the shortcut settings, it’s worth knowing these are two different things:
- Maximize (Meta+PgUp in Plasma) fills the screen but keeps the titlebar and panel visible.
- Full screen hides everything, panel included.
For a writing or chat app, maximized is often what you actually want day-to-day, with true full screen reserved for distraction-free focus sessions.
The key insight to take away: on KDE, if an app won’t do something with its window, ask the window manager instead. KWin outranks the app.