Welcome to React Native! This page will help you install React Native on
your system, so that you can build apps with it right away. If you already
have React Native installed, you can skip ahead to the
[Tutorial](/react-native/docs/tutorial.html).
The instructions are a bit different depending on your development operating system, and whether you want to start developing for iOS or Android. If you
want to develop for both iOS and Android, that's fine - you just have to pick
one to start with, since the setup is a bit different.
<div>Unfortunately, Apple only lets you develop for iOS on a Mac. If you want to build an iOS app but you don't have a Mac yet, you can try starting with the <ahref=""onclick="display('platform', 'android')">Android</a> instructions instead.</div>
We recommend installing Node.js and Python2 via [Chocolatey](https://chocolatey.org), a popular package manager for Windows. Open a Command Prompt as Administrator, then run:
The easiest way to install Xcode is via the [Mac App Store](https://itunes.apple.com/us/app/xcode/id497799835?mt=12). Installing Xcode will also install the iOS Simulator and all the necessary tools to build your iOS app.
Setting up your development environment can be somewhat tedious if you're new to Android development. If you're already familiar with Android development, there are a few things you may need to configure. In either case, please make sure to carefully follow the next few steps.
[Android Studio](https://developer.android.com/studio/install.html) provides the Android SDK and AVD (emulator) required to run and test your React Native apps.
> Android Studio requires the [Java Development Kit (JDK)](https://www.java.com/en/download/mac_download.jsp), version 1.8 or higher. You can type `javac -version` in a terminal to see what version you have, if any.
> If you've already installed Android Studio before, you can still [install HAXM](https://software.intel.com/en-us/android/articles/installation-instructions-for-intel-hardware-accelerated-execution-manager-windows) without performing a custom installation.
Click "Next" to install all of these components, then [configure VM acceleration](https://developer.android.com/studio/run/emulator-acceleration.html#vm-linux) on your system.
Android Studio installs the most recent Android SDK by default. React Native, however, requires the `Android 6.0 (Marshmallow)` SDK. To install it, launch the SDK Manager, click on "Configure" in the "Welcome to Android Studio" screen.
> The SDK Manager can also be found within the Android Studio "Preferences" menu, under **Appearance & Behavior** → **System Settings** → **Android SDK**.
Select "SDK Platforms" from within the SDK Manager, then check the box next to "Show Package Details". Look for and expand the `Android 6.0 (Marshmallow)` entry, then make sure the following items are all checked:
Next, select "SDK Tools" and check the box next to "Show Package Details" here as well. Look for and expand the "Android SDK Build Tools" entry, then make sure that `Android SDK Build-Tools 23.0.1` is selected.
> Please make sure you export the correct path for `ANDROID_HOME`. If you installed the Android SDK using Homebrew, it would be located at `/usr/local/opt/android-sdk`.
Follow the [Watchman installation guide](https://facebook.github.io/watchman/docs/install.html#build-install) to compile and install Watchman from source.
> [Watchman](https://facebook.github.io/watchman/docs/install.html) is a tool by Facebook for watching
changes in the filesystem. It is highly recommended you install it for better performance, but it's alright to skip this if you find the process to be tedious.
Once in the "AVD Manager", select your AVD and click "Start...".
> Android Studio should have set up an Android Virtual Device for you during installation, but it is very common to run into an issue where Android Studio fails to install the AVD. You may follow the [Android Studio User Guide](https://developer.android.com/studio/run/managing-avds.html) to create a new AVD manually if needed.
Use the React Native command line interface to generate a new React Native project called "AwesomeProject", then run `react-native run-ios` inside the newly created folder.
Use the React Native command line interface to generate a new React Native project called "AwesomeProject", then run `react-native run-android` inside the newly created folder:
If everything is set up correctly, you should see your new app running in your AVD shortly.
`react-native run-android` is just one way to run your app - you can also run it directly from within Android Studio or [Nuclide](https://nuclide.io/).
Use the React Native command line interface to generate a new React Native project called "AwesomeProject", then run `react-native start` inside the newly created folder to start the packager.
```
react-native init AwesomeProject
cd AwesomeProject
react-native start
```
Open a new command prompt and run `react-native run-android` inside the same folder to launch the app on your AVD.
Use the React Native command line interface to generate a new React Native project called "AwesomeProject", then run `react-native run-android` inside the newly created folder.
> If you hit a `ERROR Watcher took too long to load`, try increasing the timeout in [this file](https://github.com/facebook/react-native/blob/5fa33f3d07f8595a188f6fe04d6168a6ede1e721/packager/react-packager/src/DependencyResolver/FileWatcher/index.js#L16) (under your `node_modules/react-native/`).
> If you're targeting API level 23, the app might crash on first launch with an error smilar to `Unable to add window android.view.ViewRootImpl$W@c51fa6 -- permission denied for this window type`. To fix this, you need to go to `System settings > Apps > Configure apps > Draw over other apps` and grant the permission for the app.
NOTE: Many React Native modules haven't been tested on Marshmallow and might break. Please throughly test the app if you target API level 23 and file a bug report if you find that something is broken.
- If you want to add this new React Native code to an existing application, check out the [Integration guide](docs/integration-with-existing-apps.html).
- If you can't get this to work, see the [Troubleshooting](docs/troubleshooting.html#content) page.
- If you're curious to learn more about React Native, continue on
- If you want to add this new React Native code to an existing application, check out the [Integration guide](docs/integration-with-existing-apps.html).
