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A bash script to change the window title of Flatpak apps by patching their interpreted source files (Python/JS).
Born from trying to rename the ZapZap WhatsApp wrapper window to match my customization, because the original title is "ZapZap" and I don't like it. And then discovering that KWin's "Special Window Settings" only identifies windows, not renames them.
So i did this in my free time only for fun and for save myself time in the future if I want to change something like that.
On Wayland, no external process can change the window title of another app — the protocol simply doesn't allow it. Tools like wmctrl, xdotool, and KWin special window rules can't do it either (those are window identifiers, not title setters)
The only real way in is inside the app's own source. Many Flatpak apps are written in Python or JS, meaning their source ships readable and patchable. This script finds the window title call and replaces the string directly.
For Electron apps specifically, the JS code is bundled inside an app.asar archive — the script extracts it, patches it, and repacks it automatically.
Only tested on: Fedora 44 · KDE Plasma · Wayland
Honestly, I can't guarantee this works for every app out there, but you can try! This tool was created precisely so you don't have to keep messing with the files every time you want to do something like this! (Remember: this is for Flatpak interpreted apps)
Python apps ship their source as plain .py files, so patching is reliable.
Electron apps bundle their JS inside app.asar. The script extracts, patches, and repacks it automatically — but it only works if the title is set as a plain string literal in the code. Apps that minify or obfuscate their JS, or set the title dynamically, won't work.
Compiled bytecode, no readable source. Out of scope entirely.
git clone https://github.com/ezerevello/retitle-flatpak
cd retitle-flatpak
chmod +x install.sh
./install.shinstall.sh copies the script to ~/.local/bin and handles $PATH automatically — it detects your shell (zsh, bash, fish, ksh) and adds ~/.local/bin to your config file only if it isn't already there.
Supported shells: zsh · bash · fish · ksh
retitle-flatpak <APP_ID> "<new title>"retitle-flatpak com.rtosta.zapzap "WhatsApp"To find the App ID of any installed Flatpak:
flatpak list --app- Resolves the installation path of the Flatpak via
flatpak info --show-location - Python/GTK apps: scans
.pyfiles for any supported title pattern, shows matches and asks for confirmation, then patches withsudo sed -i - Electron apps: finds
app.asar, extracts it to a temp dir using theasartool, patches the.jsfiles inside, repacks and replaces the original withsudo - The change takes effect on next app launch
| Pattern | Framework |
|---|---|
setWindowTitle(_("Title")) |
PyQt / PySide + gettext |
setWindowTitle("Title") |
PyQt / PySide plain |
.set_title(_("Title")) |
GTK Python + gettext |
.set_title("Title") |
GTK Python plain |
.setTitle("Title") |
Electron / JS (via asar) |
For Electron apps, the script needs the asar tool. If it's not installed, the script will tell you. You can install it with:
npm install -g asarOr just have Node.js installed and the script will use npx asar automatically.
| Limitation | Details |
|---|---|
| Interpreted apps only | Works for Python and non-obfuscated JS. Compiled apps (C++, Rust, Go, Java) are out of scope. |
| Patches lost on update | Flatpak updates restore the original files. Re-run the script after every app update. |
| Translated titles | Apps using _("Title") (gettext) may revert the title at runtime based on locale. |
| Wayland only concern | On X11 you could use xdotool instead. This tool targets Wayland where that's not an option. |
| Minified Electron JS | Some Electron apps (Discord, VS Code, Signal) obfuscate their code — the title won't appear as a plain string and can't be patched this way. |
Re-run with the original title:
retitle-flatpak com.rtosta.zapzap "ZapZap"Or reinstall the app to restore all original files:
flatpak repair com.rtosta.zapzap
# or
flatpak uninstall com.rtosta.zapzap && flatpak install com.rtosta.zapzap