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README

Extension.js Version Downloads workflow discord

The cross-browser extension framework.


Logo

Extension.js makes it very easy to develop cross-browser extensions.
Developers use it due to its fast builds, simple interface, and zero-configuration setup.

Create A New Extension

npx extension create my-extension
cd my-extension
npm run dev
create-a-new-extension.mp4

Web Standards and Framework Support

For a preview of extensions running these technologies, see the templates website.

ESNext
latest
TypeScript
latest
WASM
latest
React
18+
Vue
3+
Angular
👋
Svelte
5+
Solid
👋
Preact
10+

👋 = PR Welcome!

Get Started Immediately

Use Chrome to start developing an extension from Chrome Extension Samples

See the example below where we request the sample page-redder from Google Chrome Extension Samples.

npx extension dev https://github.com/GoogleChrome/chrome-extensions-samples/tree/main/functional-samples/sample.page-redder --browser=edge
chrome-extension-sample-page-redder-on-edge.mp4

I have An Extension

usage-with-an-existing-extension.mp4

If you have an existing extension which is using a package manager, you can install the Extension.js package and manually create the scripts used to run your extension.

Step 1 - Install extension as a devDependency

npm install extension --save-dev

Step 2 - Link your npm scripts with the executable Extension.js commands

{
  "scripts": {
    "build": "extension build",
    "dev": "extension dev",
    "preview": "extension preview"
  },
  "devDependencies": {
    // ...other dependencies
    "extension": "latest"
  }
}

Done. You are all set!

  • To develop the extension, run npm run dev.
  • To build the extension in production mode, run npm run build.
  • To visualize the extension in production mode, run npm run build and npm run preview.

Using a specific browser for development

Desktop Browsers

Chrome
Chromium
☑️
Edge
Firefox
Opera
☑️
Safari
⛔️

The browsers listed above represent those with official extension stores. Note that Chromium-based browsers (like Arc, Brave, Vivaldi, and many others) are theoretically supported through the Chrome/Chromium compatibility layer.

Mobile Browsers

Firefox (Android)
⛔️
Safari (iOS)
⛔️

License

MIT (c) Cezar Augusto and the Extension.js authors.