create-react-app/README.md

# Create React App [![Build Status](https://travis-ci.org/facebook/create-react-app.svg?branch=master)](https://travis-ci.org/facebook/create-react-app) [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-green.svg)](https://github.com/facebook/create-react-app/pulls) 

Create React apps with no build configuration.

- [Creating an App](#creating-an-app) – How to create a new app.
- [User Guide](https://facebook.github.io/create-react-app/docs/folder-structure) – How to develop apps bootstrapped with Create React App.

Create React App works on macOS, Windows, and Linux.<br>
If something doesn’t work, please [file an issue](https://github.com/facebook/create-react-app/issues/new).

## Quick Overview

```sh
npx create-react-app my-app
cd my-app
npm start
```

_([npx](https://medium.com/@maybekatz/introducing-npx-an-npm-package-runner-55f7d4bd282b) comes with npm 5.2+ and higher, see [instructions for older npm versions](https://gist.github.com/gaearon/4064d3c23a77c74a3614c498a8bb1c5f))_

Then open [http://localhost:3000/](http://localhost:3000/) to see your app.<br>
When you’re ready to deploy to production, create a minified bundle with `npm run build`.

<p align='center'>
<img src='https://cdn.rawgit.com/facebook/create-react-app/27b42ac/screencast.svg' width='600' alt='npm start'>
</p>

### Get Started Immediately

You **don’t** need to install or configure tools like Webpack or Babel.<br>
They are preconfigured and hidden so that you can focus on the code.

Just create a project, and you’re good to go.

## Creating an App

**You’ll need to have Node 8.10.0 or later on your local development machine** (but it’s not required on the server). You can use [nvm](https://github.com/creationix/nvm#installation) (macOS/Linux) or [nvm-windows](https://github.com/coreybutler/nvm-windows#node-version-manager-nvm-for-windows) to easily switch Node versions between different projects.

To create a new app, you may choose one of the following methods:

### npx

```sh
npx create-react-app my-app
```

_([npx](https://medium.com/@maybekatz/introducing-npx-an-npm-package-runner-55f7d4bd282b) comes with npm 5.2+ and higher, see [instructions for older npm versions](https://gist.github.com/gaearon/4064d3c23a77c74a3614c498a8bb1c5f))_

### npm

```sh
npm init react-app my-app
```

_`npm init <initializer>` is available in npm 6+_

### Yarn

```sh
yarn create react-app my-app
```

_`yarn create` is available in Yarn 0.25+_

It will create a directory called `my-app` inside the current folder.<br>
Inside that directory, it will generate the initial project structure and install the transitive dependencies:

```
my-app
├── README.md
├── node_modules
├── package.json
├── .gitignore
├── public
│   ├── favicon.ico
│   ├── index.html
│   └── manifest.json
└── src
    ├── App.css
    ├── App.js
    ├── App.test.js
    ├── index.css
    ├── index.js
    ├── logo.svg
    └── serviceWorker.js
```

No configuration or complicated folder structures, just the files you need to build your app.<br>
Once the installation is done, you can open your project folder:

```sh
cd my-app
```

Inside the newly created project, you can run some built-in commands:

### `npm start` or `yarn start`

Runs the app in development mode.<br>
Open [http://localhost:3000](http://localhost:3000) to view it in the browser.

The page will automatically reload if you make changes to the code.<br>
You will see the build errors and lint warnings in the console.

<p align='center'>
<img src='https://cdn.rawgit.com/marionebl/create-react-app/9f62826/screencast-error.svg' width='600' alt='Build errors'>
</p>

### `npm test` or `yarn test`

Runs the test watcher in an interactive mode.<br>
By default, runs tests related to files changed since the last commit.

[Read more about testing.](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#running-tests)

### `npm run build` or `yarn build`

Builds the app for production to the `build` folder.<br>
It correctly bundles React in production mode and optimizes the build for the best performance.

The build is minified and the filenames include the hashes.<br>

Your app is ready to be deployed.

## User Guide

You can find detailed instructions on using Create React App and many tips in [its documentation](https://facebook.github.io/create-react-app/).

## How to Update to New Versions?

Please refer to the [User Guide](https://facebook.github.io/create-react-app/docs/updating-to-new-releases) for this and other information.

## Philosophy

- **One Dependency:** There is just one build dependency. It uses Webpack, Babel, ESLint, and other amazing projects, but provides a cohesive curated experience on top of them.

- **No Configuration Required:** You don't need to configure anything. Reasonably good configuration of both development and production builds is handled for you so you can focus on writing code.

- **No Lock-In:** You can “eject” to a custom setup at any time. Run a single command, and all the configuration and build dependencies will be moved directly into your project, so you can pick up right where you left off.

## What’s Included?

Your environment will have everything you need to build a modern single-page React app:

- React, JSX, ES6, TypeScript and Flow syntax support.
- Language extras beyond ES6 like the object spread operator.
- Autoprefixed CSS, so you don’t need `-webkit-` or other prefixes.
- A fast interactive unit test runner with built-in support for coverage reporting.
- A live development server that warns about common mistakes.
- A build script to bundle JS, CSS, and images for production, with hashes and sourcemaps.
- An offline-first [service worker](https://developers.google.com/web/fundamentals/getting-started/primers/service-workers) and a [web app manifest](https://developers.google.com/web/fundamentals/engage-and-retain/web-app-manifest/), meeting all the [Progressive Web App](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#making-a-progressive-web-app) criteria. (_Note: Using the service worker is opt-in as of `react-scripts@2.0.0` and higher_)
- Hassle-free updates for the above tools with a single dependency.

Check out [this guide](https://github.com/nitishdayal/cra_closer_look) for an overview of how these tools fit together.

The tradeoff is that **these tools are preconfigured to work in a specific way**. If your project needs more customization, you can ["eject"](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#npm-run-eject) and customize it, but then you will need to maintain this configuration.

## Popular Alternatives

Create React App is a great fit for:

- **Learning React** in a comfortable and feature-rich development environment.
- **Starting new single-page React applications.**
- **Creating examples** with React for your libraries and components.

Here’s a few common cases where you might want to try something else:

- If you want to **try React** without hundreds of transitive build tool dependencies, consider [using a single HTML file or an online sandbox instead](https://reactjs.org/docs/try-react.html).

- If you need to **integrate React code with a server-side template framework** like Rails, Django or Symfony, or if you’re **not building a single-page app**, consider using [nwb](https://github.com/insin/nwb), or [Neutrino](https://neutrino.js.org/) which are more flexible. For Rails specifically, you can use [Rails Webpacker](https://github.com/rails/webpacker). For Symfony, try [Symfony's Webpack Encore](https://symfony.com/doc/current/frontend/encore/reactjs.html).

- If you need to **publish a React component**, [nwb](https://github.com/insin/nwb) can [also do this](https://github.com/insin/nwb#react-components-and-libraries), as well as [Neutrino's react-components preset](https://neutrino.js.org/packages/react-components/).

- If you want to do **server rendering** with React and Node.js, check out [Next.js](https://github.com/zeit/next.js/) or [Razzle](https://github.com/jaredpalmer/razzle). Create React App is agnostic of the backend, and just produces static HTML/JS/CSS bundles.

- If your website is **mostly static** (for example, a portfolio or a blog), consider using [Gatsby](https://www.gatsbyjs.org/) instead. Unlike Create React App, it pre-renders the website into HTML at the build time.

- Finally, if you need **more customization**, check out [Neutrino](https://neutrino.js.org/) and its [React preset](https://neutrino.js.org/packages/react/).

All of the above tools can work with little to no configuration.

If you prefer configuring the build yourself, [follow this guide](https://reactjs.org/docs/add-react-to-an-existing-app.html).

## Contributing

We'd love to have your helping hand on `create-react-app`! See [CONTRIBUTING.md](CONTRIBUTING.md) for more information on what we're looking for and how to get started.

## React Native

Looking for something similar, but for React Native?<br>
Check out [Expo CLI](https://github.com/expo/expo-cli).

## Acknowledgements

We are grateful to the authors of existing related projects for their ideas and collaboration:

- [@eanplatter](https://github.com/eanplatter)
- [@insin](https://github.com/insin)
- [@mxstbr](https://github.com/mxstbr)

## License

Create React App is open source software [licensed as MIT](https://github.com/facebook/create-react-app/blob/master/LICENSE).