> ## Documentation Index
> Fetch the complete documentation index at: https://docs.browserbase.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Browser extensions

> Augment your browser sessions with your own Chrome extensions.

You can load your own Chrome extensions into Browserbase sessions.

## Sample extension

Here's a simple example extension that modifies page titles. It consists of two files:

<CodeGroup>
  ```js manifest.json theme={null}
  {
      "manifest_version": 3,
      "version": "1.0",
      "name": "My Test Extension",
      "description": "Test of a simple browser extension",
      "content_scripts": [
          {
              "matches": [
                  "https://www.sfmoma.org/*"
              ],
              "js": [
                  "content-script.js"
              ]
          }
      ]
  }
  ```

  ```js content-script.js theme={null}
  document.title += " -- Title updated by browser extension";
  ```
</CodeGroup>

<Note>
  You can download this sample extension
  [here](http://browser-tests-alpha.vercel.app/demo-extension.zip). The
  extension must be in a `.zip` file format with a `manifest.json` at the root.
  The file must be less than or equal to 100 MB.
</Note>

## Upload your extension

Once you have your extension files zipped up, you can upload it using the SDK:

<Tabs>
  <Tab title="Node.js">
    ```javascript theme={null}
    import { Browserbase } from '@browserbasehq/sdk';
    import fs from 'fs';

    const bb = new Browserbase({ apiKey: process.env.BROWSERBASE_API_KEY });

    const file = fs.createReadStream('extension.zip');
    const extension = await bb.extensions.create({ file });

    const extensionId = extension.id;
    console.log(`Extension uploaded with ID: ${extensionId}`);
    ```
  </Tab>

  <Tab title="Python">
    ```python theme={null}
    from browserbase import Browserbase
    import os

    bb = Browserbase(api_key=os.environ["BROWSERBASE_API_KEY"])

    with open("extension.zip", "rb") as f:
        extension = bb.extensions.create(file=f)

    extension_id = extension.id
    print(f"Extension uploaded with ID: {extension_id}")
    ```
  </Tab>
</Tabs>

## Create a session with your extension

To use your extension, create a new session with the extension enabled:

<Tabs>
  <Tab title="Node.js">
    ```javascript theme={null}
    import { Browserbase } from '@browserbasehq/sdk';

    const bb = new Browserbase({ apiKey: process.env.BROWSERBASE_API_KEY });

    const session = await bb.sessions.create({
        extensionId: 'your-extension-id'
    });

    console.log(`Session created with ID: ${session.id}`);
    ```
  </Tab>

  <Tab title="Python">
    ```python theme={null}
    from browserbase import Browserbase
    import os

    bb = Browserbase(api_key=os.environ["BROWSERBASE_API_KEY"])

    session = bb.sessions.create(
        extension_id="your-extension-id"
    )

    print(f"Session created with ID: {session.id}")
    ```
  </Tab>
</Tabs>

<Note>
  Starting a new session with an extension can increase the session creation
  time. The browser must be restarted to load the extension, which itself has
  nonzero load time.
</Note>

## Verify the extension

To verify your extension is working:

1. Connect to your session using Playwright or Selenium
2. Navigate to a page where your extension should be active
3. Check for the expected modifications or behaviors

For the sample extension above, navigate to [https://www.sfmoma.org](https://www.sfmoma.org) and verify that the page title has been modified with the additional text.