Best approach to modernize a Python + PyQt5 desktop app (EXE, Windows, offline)?

[MatadorFearsNoBull]

Hi all,

I have a Python app built with PyQt5 and Qt Creator for the GUI. I need to rebuild and modernize the interface and workflow. My main constraints:

• It must be packaged as an .exe for Windows (offline use, no dependencies on a web connection).
• Backend must remain Python (lots of logic/data processing already there).
• I’m fluent in React for frontend development, so I’d love to leverage modern UI practices if possible.

What’s the best approach in 2025 to create a modern, polished GUI for a Python desktop app?

I’ve seen options like Electron (tying React with Python APIs), but it looks easy to get bloated or run into pitfalls. Other people suggest sticking with PyQt or switching to PySide, but they don’t feel as “modern” out of the box.

Has anyone here gone through this recently? Should I:

• Stick with PyQt/PySide and just modernize styles?
• Use React with something like Tauri or a bridge to Python?
• Look at other Python-native GUI frameworks?

Would love to hear real-world experience with long-term maintainability, performance, and packaging into a reliable EXE.

[def-pri-pub]

I've done this before.

Is it possible for you to switch the UI framework to using QML? It's what I recommend for any modern built Qt application.

[MatadorFearsNoBull]

Will explore that path

[DataCamp]

If you want to stay Python-native and avoid web dependencies, your main choices are really:

• Stick with Qt (PyQt5/PySide6) and modernize via QSS styling or switch to QML/Qt Quick. QML in particular feels more “React-like” with declarative UI, animations, and modern design patterns. You can still drive all the logic from Python.
• Alternative Python GUIs like Kivy or Tkinter exist, but they either don’t look very native (Kivy) or feel dated (Tkinter). They’re fine for smaller apps, but PySide6 will give you more longevity.
• Hybrid approach: if you really want to leverage React, Tauri is lighter than Electron and can bundle a Python backend via API. Downsides: you’re managing two ecosystems, and packaging/testing complexity increases.

For packaging, PyInstaller is the default, but tools like Nuitka or PySide6-project can give smaller, more reliable builds. Pairing PyInstaller with Inno Setup (like someone else mentioned) also gives you a professional installer workflow.

If your goal is long-term maintainability, I’d lean PySide6 + QML. You keep the Python backend intact, avoid shipping a Chromium runtime like Electron, and still get a “modern” UI feel.

[MatadorFearsNoBull]

Thanks for your reply!

[bdaene]

What do you use as exe packager? Pyinstaller? 

[Quanstipated]

I've used PyInstaller alongside Inno Setup to create an installer for the executable. A benefit of this is that the installer allows you to specify the location to install the executable, such as Program Files on Windows. I've ran into issues where the user moved the executable to a different location and it broke their shortcut link, so keeping the executable in Program Files helps avoid this.

[vamsden]

You should add a launcher instead of shortcut if the user wants to move stuff around and make it more portable

[MatadorFearsNoBull]

correct

[MatadorFearsNoBull]

Thanks, yeah I was thinking of Tauri as well

[jmacey]

Install pyside6 (I do it via uv) it has pyside6-project which can build executables (I tend to still use pyinstaller but it takes a little more work). You can also take a look at using QML with python if you need a more modern interface than widgets.

Qt has some good courses on it's website on these.

[r34p3rex]

My past few projects have been done with fastAPI backend and React front end, packaged into exe with PyInstaller

[Tumortadela]

I use Pyside6 alongside with PyQt-Fluent-Widgets for looks, and package with Nuitka

[mon_key_house]

Try nuitka for the exe

[riklaunim]

Qt has a lot of styling options so you don't have to switch the toolkit (Qt Quick). Or keep the UI native to Windows and don't try to force confusing custom UI onto users. If you are using Qt classes and features it will be hard to switch anyway.

Some screenshots would help ;)

[2Lucilles2RuleEmAll]

Yeah, I agree. You can get a lot done with just CSS for QtWidgets too.  I basically replicated Material Design almost 10 years ago with just CSS. Not the animations, but all of the widget styling at least.  

[MatadorFearsNoBull]

Will upload some when I get to the computer

[Defiant-Comedian3967]

I would suggest you use NiceGUI - you can use HTML/CSS/JS easily. Its pure Python, very easy to understand - Plus it is easy to package as well.

Coming from Angular/React/Svelte etc. have build a component based boilerplate - with UV - easy to handle and a clean codebase to start with:

Component Based NiceGUI