How to make an extension for a browser on python

Learn how to create a browser extension in Python with an example project that covers the basics of browser extension development.

Creating a Simple Browser Extension with Python

Creating a browser extension with Python is a simple and powerful way to extend the functionality of a browser. In this tutorial, we will be creating a simple browser extension that allows the user to open a web page in a new tab with a single click. We will use the webbrowser module for this purpose.

The first step is to create a folder that will contain our extension files. Inside this folder, create a file called manifest.json and add the following code:

  "manifest_version": 2,
  "name": "My Extension",
  "version": "1.0",
  "background": {
    "scripts": ["background.js"]
  "permissions": [

The manifest.json file is the main configuration file for our extension. It tells the browser which scripts to load, what permissions the extension has, and what its name and version are. In this case, we are telling the browser to load a script called background.js. This will be a JavaScript file that contains our code.

Next, we need to create the background.js file. This will contain our code that will be executed when the extension is loaded. Add the following code to the file:

chrome.tabs.onUpdated.addListener(function(tabId, changeInfo, tab) {
  chrome.tabs.executeScript(tabId, {
    code: 'alert("Hello from My Extension!");'

This code will run when a tab is updated (for example, when a page is loaded). It will display an alert that says "Hello from My Extension!".

Finally, we need to create the file that will be used to open a web page in a new tab. Add the following code to the file:

import webbrowser

def open_url(url):

This code uses the webbrowser module to open a new tab with the specified URL. Note that this code will only be executed when the extension is loaded, not when it is installed.

Now we have all the files we need to create our browser extension. To install it, we need to open the browser's extension page (usually this is available under the "Settings" or "Extensions" menu). Then, click the "Load Unpacked" button, select the folder containing our extension files, and click "OK". The extension should now be installed and active.

To test our extension, we can open a web page and click the "My Extension" button. This will execute the background.js file, which will display the alert we added earlier. We can also use the open_url function in our file to open a web page in a new tab.

That's all there is to it! We have created a simple browser extension with Python, and we can now use it to extend the browser's functionality.

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