Running On Device - React Native

1. Enable Debugging over USB​

Most Android devices can only install and run apps downloaded from Google Play, by default. You will need to enable USB Debugging on your device in order to install your app during development.

To enable USB debugging on your device, you will first need to enable the "Developer options" menu by going to Settings → About phone → Software information and then tapping the Build number row at the bottom seven times. You can then go back to Settings → Developer options to enable "USB debugging".

2. Plug in your device via USB​

Let's now set up an Android device to run our React Native projects. Go ahead and plug in your device via USB to your development machine.

Now check that your device is properly connecting to ADB, the Android Debug Bridge, by running adb devices.shell$ adb devicesList of devices attachedemulator-5554 offline # Google emulator14ed2fcc device # Physical device

Seeing device in the right column means the device is connected. You must have only one device connected at a time.note

If you see unauthorized in the list you will need to run adb reverse tcp:8081 tcp:8081 and press allow USB debugging on the device.

3. Run your app​

From the root of your project; type the following in your command prompt to install and launch your app on the device:

• npm
• Yarn

If you get a "bridge configuration isn't available" error, see Using adb reverse.tip

You can also use the React Native CLI to generate and run a release build (e.g. from the root of your project: yarn android --mode release).

Connecting to the development server

You can also iterate quickly on a device by connecting to the development server running on your development machine. There are several ways of accomplishing this, depending on whether you have access to a USB cable or a Wi-Fi network.

Method 1: Using adb reverse (recommended)​

You can use this method if your device is running Android 5.0 (Lollipop) or newer, it has USB debugging enabled, and it is connected via USB to your development machine.

Run the following in a command prompt:shell$ adb -s<device name> reverse tcp:8081 tcp:8081

To find the device name, run the following adb command:shell$ adb devices

You can now enable Fast Refresh from the Dev Menu. Your app will reload whenever your JavaScript code has changed.

Method 2: Connect via Wi-Fi​

You can also connect to the development server over Wi-Fi. You'll first need to install the app on your device using a USB cable, but once that has been done you can debug wirelessly by following these instructions. You'll need your development machine's current IP address before proceeding.

You can find the IP address in System Settings (or System Preferences) → Network.

1. Make sure your laptop and your phone are on the same Wi-Fi network.
2. Open your React Native app on your device.
3. You'll see a red screen with an error. This is OK. The following steps will fix that.
4. Open the in-app Dev Menu.
5. Go to Dev Settings → Debug server host & port for device.
6. Type in your machine's IP address and the port of the local dev server (e.g. 10.0.1.1:8081).
7. Go back to the Dev Menu and select Reload JS.

You can now enable Fast Refresh from the Dev Menu. Your app will reload whenever your JavaScript code has changed.

Building your app for production​

You have built a great app using React Native, and you are now itching to release it in the Play Store. The process is the same as any other native Android app, with some additional considerations to take into account. Follow the guide for generating a signed APK to learn more.