Skip to content
Branch: master
Go to file

Latest commit


Failed to load latest commit information.
Latest commit message
Commit time


Build Status Backers on Open Collective Sponsors on Open Collective

Pack JS code into a single bundle fast & easy.


Because JavaScript builds should be faster!

Here is an example benchmark of bundling ~1600 modules together.

Fastpack Parcel Webpack
initial build 0.730s 9.740s 3.625s
persistent cache 0.171s 1.218s N/A
watch mode 0.084s 0.503s 0.473s

Getting Started

Let's try building a simple React application!

  $ mkdir react-app
  $ cd react-app
  $ yarn init -y
  $ yarn add react react-dom
  $ yarn add --dev fastpack
  $ yarn add --dev babel-loader babel-preset-react-app style-loader css-loader url-loader


import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';
import App from './App';

ReactDOM.render(<App />, document.getElementById('root'));


body {
  margin: 0;
  padding: 0;
  font-family: sans-serif;


import React, { Component } from 'react';
import logo from './logo.svg';
import './App.css';

class App extends Component {
  render() {
    return (
      <div className="App">
        <header className="App-header">
          <img src={logo} className="App-logo" alt="logo" />
          <h1 className="App-title">Welcome to React</h1>
        <p className="App-intro">
          To get started, edit <code>src/App.js</code> and save to reload.

export default App;


.App {
  text-align: center;

.App-logo {
  animation: App-logo-spin infinite 20s linear;
  height: 80px;

.App-header {
  background-color: #222;
  height: 150px;
  padding: 20px;
  color: white;

.App-title {
  font-size: 1.5em;

.App-intro {
  font-size: large;

@keyframes App-logo-spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }


<!DOCTYPE html>
<head><title>React App</title></head>
<div id="root"></div>
<script type="text/javascript" src="./bundle/index.js"></script>

Also, add the src/logo.svg of your choice. Now let's add some config:


    "presets": ["react-app"]

And the fastpack configuration as well:


    "entryPoints": ["src/index.js"],
    "preprocess": [
            "re": "^src.+\\.js$",
            "process": "babel-loader"
            "re": "\\.svg$",
            "process": "url-loader"
            "re": "\\.css$",
            "process": "style-loader!css-loader"

The above configuration can be alternatively specified using command-line arguments, for more details run:

  $ node_modules/.bin/fpack --help

We are good to go! Now run:

  $ node_modules/.bin/fpack build --dev
  Cache: empty
  Done in 0.817s. Bundle: 942Kb. Modules: 30.
  $ open index.html

Voila! Now try running it again and see the power of the persistent cache!

  $ node_modules/.bin/fpack build --dev
  Cache: used
  Done in 0.032s. Bundle: 942Kb. Modules: 30.

For more configuration options and usage scenarios see Documentation.

Have a question or want to contribute? Join us on Discord!


This project exists thanks to all the people who contribute.

Special thanks to @camsong for providing the fastpack name on!


Thank you to all our backers! 🙏 [Become a backer]


Support this project by becoming a sponsor. Your logo will show up here with a link to your website. [Become a sponsor]

You can’t perform that action at this time.