pywebview

pywebview is a lightweight native webview wrapper that displays HTML content in a native GUI window.

Key Features:

• Native GUI Backends: Uses WinForms on Windows, Cocoa on macOS, and QT or GTK on Linux.
• Two-way Communication: Enables interaction between JavaScript and Python.
• Built-in HTTP Server: Includes a server to serve local content.
• DOM Support: Provides DOM support directly in Python.
• Window Management: Includes window manipulation, an event system, application menus, and native dialogs.
• Small Footprint: Does not bundle heavy GUI toolkits or web renderers when frozen, keeping executable sizes small.

To launch a basic window, use webview.create_window to define the window title and the URL (or HTML content) to load, then call webview.start() to begin the GUI loop.

Windows created before webview.start() appear when the loop starts. Windows created after the loop starts appear immediately. You can manage multiple windows via webview.windows (a list of windows in creation order) and access the currently focused window using webview.active_window().

import webview

window = webview.create_window('Woah dude!', 'https://pywebview.flowrl.com')
webview.start()

To create a basic native window that displays a web URL, use webview.create_window() to define the window properties and webview.start() to launch the application loop.

import webview
webview.create_window('Hello world', 'https://pywebview.flowrl.com/')
webview.start()

Python to JavaScript

Use window.evaluate_js(code) to run JS from Python. To handle asynchronous JS (Promises), provide a callback: window.evaluate_js(code, callback).

JavaScript to Python

To expose Python methods to the JavaScript window object, pass an instance of a class to the js_api parameter in webview.create_window(url, js_api=api_instance).

Methods of the class will be accessible in JavaScript via window.pywebview.api.methodName(). You can also use window.expose(func) to expose individual functions during runtime.

import webview

class Api():
  def log(self, value):
    print(value)

webview.create_window("Test", html="<button onclick='pywebview.api.log(\"Woah dude!\")'>Click me</button>", js_api=Api())
webview.start()

To subscribe to lifecycle or management events on a window object, use the += syntax. To unsubscribe, use the -= syntax. Duplicate subscriptions are automatically ignored.

When writing an event handler, the first positional argument must be the window object itself.

Note on threading: Most window events are asynchronous and execute in separate threads. However, before_show, before_load, and initialized are synchronous and will block the main thread until the handler completes.

You can use the JS API bridge to enable communication between Python and JavaScript without an external web server. To serve static content, set the entrypoint URL to a local relative path; pywebview will automatically start a built-in HTTP server.

To create the bridge, use webview.create_window(..., js_api=Api()) or the window.expose function.

In a frameless window, you can make specific HTML elements act as handles to move or drag the window by adding the CSS class pywebview-drag-region to them.

You can customize this behavior by re-assigning the webview.settings['DRAG_REGION_SELECTOR'] property in Python.

<div class='pywebview-drag-region'>Now window can be moved by dragging this DIV.</div>

For macOS, you may need pyobjc. While it is preinstalled with the Python bundled in macOS, standalone Python installations require it. You do not need the full package; the following specific packages are sufficient:

• pyobjc-core
• pyobjc-framework-Cocoa
• pyobjc-framework-Quartz
• pyobjc-framework-WebKit
• pyobjc-framework-security

You can also use QT on macOS.