So you created your app, but there are still some things to do before publishing a React Native app on Android.

Remove Debug Commands

This one might be obvious, but make sure to really remove all debug console.logs and unnecessary Redux middleware like redux-logger, otherwise you might feel a drastic performance drop in your release build.

Create a signed APK

When you upload your app to the Google Play Store or test it on your real device instead of the emulator, your APK has to be signed for security reasons. There is an article about how to sign your React Native APK in the React Native documentation. Here are the steps summarized again:

1. Go to android/app in your project folder and run

keytool -genkey -v -keystore my-release-key.keystore -alias my-key-alias -keyalg RSA -keysize 2048 -validity 10000

2. Add global gradle variables by appending

   MYAPP_RELEASE_STORE_FILE=my-release-key.keystore
   MYAPP_RELEASE_KEY_ALIAS=my-key-alias
   MYAPP_RELEASE_STORE_PASSWORD=*****
   MYAPP_RELEASE_KEY_PASSWORD=*****

   to ~/.gradle/gradle.properties (or C:\Users\USERNAME\.gradle\gradle.properties on Windows)

3. Edit android/app/build.gradle to use the global gradle variables:

   android {
       ...
       defaultConfig { ... }
       signingConfigs {
           release {
               storeFile file(MYAPP_RELEASE_STORE_FILE)
               storePassword MYAPP_RELEASE_STORE_PASSWORD
               keyAlias MYAPP_RELEASE_KEY_ALIAS
               keyPassword MYAPP_RELEASE_KEY_PASSWORD
           }
       }
       buildTypes {
           release {
               ...
               signingConfig signingConfigs.release
           }
       }
   }

4. You can now compile it and deploy it to your device by running

react-native run-android --variant=release
The app-release.apk can be found in android/app/build/outputs/apk.

Remember to keep your keystore private, remove it from version control and don’t lose it, otherwise you can’t update your app anymore.

Remove unnecessary permission

If you are like me, you don’t like having Android permissions in your app that you don’t use. React Native automatically injects some permissions into your app, you can see them at android/app/build/intermediates/manifests/full/release/AndroidManifest.xml. There, the permissions are listed as:

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />

React Native needs these because a lot of them are used during development, INTERNET for hot-reloading, or SYSTEM_ALERT_WINDOW to show the yellow warning and red error messages. If your app doesn’t require them, it’s good practice to remove them. What worked for me was the following:

1. In android/app/src/main/AndroidManifest.xml (!) add

   <uses-permission android:name="android.permission.READ_PHONE_STATE" tools:node="remove"/>

   to remove the READ_PHONE_STATE permission.

2. You want to remove SYSTEM_ALERT_WINDOW only in release mode. What worked for me was creating a new AndroidManifest.xml in android/app/src/release with the following contents:

   <manifest
       xmlns:android="http://schemas.android.com/apk/res/android"
       xmlns:tools="http://schemas.android.com/tools"
       >
   
       <!-- These are added by React Native for debug mode, but actually aren't needed in releasemode -->
       <uses-permission tools:node="remove" android:name="android.permission.SYSTEM_ALERT_WINDOW" />
   </manifest>

   If you are having trouble with this, you can read more at this GitHub Issue.

Upgrade Version Code in React Native

If you want to push an update to Google Play, you must increment the version code of your app. This can be found in android/app/build.gradle as:

android {
    ...

    defaultConfig {
        ...
        versionCode 2
        versionName "1.0"
    }
}