Skip to content

Build Python Desktop Apps with HTML, CSS, and JavaScript

Pytonium embeds the Chromium Embedded Framework in Python, giving you the full power of modern web technologies for your desktop application UI.

Get Started in Seconds

pip install Pytonium

import time
from Pytonium import Pytonium

p = Pytonium()
p.initialize("https://example.com", 800, 600)

while p.is_running():
    time.sleep(0.01)
    p.update_message_loop()

That is a complete, runnable Pytonium application. It opens a native window displaying a web page, and runs until the user closes it.

Get Started API Reference Examples

Features

Chromium Rendering

Full Chromium browser engine powered by CEF 145 (Chromium 145). Render any HTML, CSS, and JavaScript your browser can -- inside a native desktop window.

Python-JS Bridge

Call Python functions from JavaScript and return values via Promises. Bind individual functions or entire objects with a single method call.

State Management

Shared state between Python and JavaScript with event subscriptions. Set state from Python, subscribe from JS, and react to changes on either side.

Reactive Components

Build UIs entirely in Python with reactive state bindings. State changes trigger surgical DOM updates -- no virtual DOM, no JavaScript framework needed.

Custom Schemes

Register custom URL protocols (e.g., myapp://) for loading local files. Serve your HTML, CSS, JS, and assets from your project directory without a web server.

Context Menus

Add custom right-click menu entries with Python callbacks. Group entries into namespaces and switch between them at runtime.

Frameless Windows

Build custom window chrome with HTML/CSS, Electron-style. Control minimize, maximize, close, drag, and resize entirely from your frontend.

Multi-Instance

Run multiple browser windows in a single process. Each window gets its own bindings, state, and lifecycle while sharing a single CEF runtime.

TypeScript Definitions

Auto-generate .d.ts files for IDE auto-completion. Your bound Python functions appear in VS Code with full type information.

Async Support

asyncio integration with run_pytonium_async. Drop the manual while-loop and run Pytonium alongside other async tasks in your application.

Cross-Platform

Windows 11 and Linux support, Python 3.10+. Build on one platform and deploy on both with the same Python code and web UI.

Next Steps

  • Installation -- Install Pytonium and verify your setup.
  • Quick Start -- Learn the core concepts: message loops, custom schemes, and the PytoniumReady event.
  • Your First App -- Build a complete app with Python-JS communication and state management.
  • API Reference -- Full reference for the Pytonium class and all its methods.
  • Examples -- Browse example applications from simple to complex.

Platform Support

Pytonium is tested on Windows 11 and Linux with Python 3.10+. macOS support is not yet available.