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Add Firebase to your Unity project

Power up your Unity games with our Firebase Unity SDKs.

To show how easy it is to plug Firebase into your Unity project, we made a sample game, MechaHamster, that you can download from GitHub, the App Store, and the Google Play Store.

MechaHamster (GitHub)

MechaHamster (App Store)

MechaHamster (Play Store)


Find out more information about powering up your games with Firebase at our Firebase games page.

Already added Firebase to your Unity project? Make sure that you're using the latest version of the Firebase Unity SDK.

Prerequisites

  • Install Unity 5.3 or later.

  • (iOS only) Install the following:

    • Xcode 9.4.1 or later
    • CocoaPods 1.9.0 or later
  • Make sure that your Unity project meets these requirements:

    • For iOS — targets iOS 10 or later
    • For Android — targets API level 16 (Jelly Bean) or later
  • Set up a physical device or use an emulator to run your app.

    • For iOS — Set up a physical iOS device or use the iOS simulator.

    • For AndroidEmulators must use an emulator image with Google Play.

If you don't already have a Unity project and just want to try out a Firebase product, you can download one of our quickstart samples.

Step 1: Create a Firebase project

Before you can add Firebase to your Unity project, you need to create a Firebase project to connect to your Unity project. Visit Understand Firebase Projects to learn more about Firebase projects.

Step 2: Register your app with Firebase

You can register one or more apps or games to connect with your Firebase project.

  1. Go to the Firebase console.

  2. In the center of the project overview page, click the Unity icon () to launch the setup workflow.

    If you've already added an app to your Firebase project, click Add app to display the platform options.

  3. Select which build target of your Unity project that you’d like to register, or you can even select to register both targets now at the same time.

  4. Enter your Unity project’s platform-specific ID(s).

    • For iOS — Enter your Unity project’s iOS ID in the iOS bundle ID field.

    • For Android — Enter your Unity project’s Android ID in the Android package name field.
      The terms package name and application ID are often used interchangeably.

  5. (Optional) Enter your Unity project’s platform-specific nickname(s).
    These nicknames are internal, convenience identifiers and are only visible to you in the Firebase console.

  6. Click Register app.

Step 3: Add Firebase configuration files

  1. Obtain your platform-specific Firebase configuration file(s) in the Firebase console setup workflow.

    • For iOS — Click Download GoogleService-Info.plist.

    • For Android — Click Download google-services.json.

  2. Open the Project window of your Unity project, then move your config file(s) into the Assets folder.

  3. Back in the Firebase console, in the setup workflow, click Next.

Step 4: Add Firebase Unity SDKs

  1. In the Firebase console, click Download Firebase Unity SDK, then unzip the SDK somewhere convenient.

    • You can download the Firebase Unity SDK again at any time.

    • The Firebase Unity SDK is not platform-specific.

  2. In your open Unity project, navigate to Assets > Import Package > Custom Package.

  3. From the unzipped SDK, select the supported Firebase products that you want to use in your app.

    Analytics enabled

    • Add the Firebase package for Google Analytics: FirebaseAnalytics.unitypackage
    • Add the packages for any other Firebase products you want to use in your app. For example, to use Firebase Authentication and Firebase Realtime Database:
      FirebaseAuth.unitypackage and FirebaseDatabase.unitypackage

    Analytics not enabled

    Add the packages for the Firebase products you want to use in your app. For example, to use Firebase Authentication and Firebase Realtime Database:
    FirebaseAuth.unitypackage and FirebaseDatabase.unitypackage

  4. In the Import Unity Package window, click Import.

  5. Back in the Firebase console, in the setup workflow, click Next.

Step 5: Confirm Google Play services version requirements

The Firebase Unity SDK for Android requires Google Play services, which must be up-to-date before the SDK can be used.

Add the following code at the start of your application. You can check for and optionally update Google Play services to the version that is required by the Firebase Unity SDK before calling any other methods in the SDK.

Firebase.FirebaseApp.CheckAndFixDependenciesAsync().ContinueWith(task => {
  var dependencyStatus = task.Result;
  if (dependencyStatus == Firebase.DependencyStatus.Available) {
    // Create and hold a reference to your FirebaseApp,
    // where app is a Firebase.FirebaseApp property of your application class.
       app = Firebase.FirebaseApp.DefaultInstance;

    // Set a flag here to indicate whether Firebase is ready to use by your app.
  } else {
    UnityEngine.Debug.LogError(System.String.Format(
      "Could not resolve all Firebase dependencies: {0}", dependencyStatus));
    // Firebase Unity SDK is not safe to use here.
  }
});

You’re all set! Your Unity project is registered and configured to use Firebase.

Known issues

.NET compatibility when using Unity 2017.x and later

Firebase supports .NET 4.x as an experimental build option in Unity 2017 and later. Firebase plugins use components of the Parse SDK to provide some .NET 4.x classes in earlier versions of .NET.

Therefore, the Firebase Unity SDK version 5.4.0 and later provide plugins that are compatible with either .NET 3.x or .NET 4.x in dotnet3 and dotnet4 directories of the Firebase Unity SDK.

If you import a Firebase plugin that is incompatible with the .NET version enabled in your project, you'll see compile errors from some types in the .NET framework that are implemented by the Parse SDK.

To resolve the compilation error, if you're using .NET 3.x:

  1. Remove or disable the following DLLs for all platforms:
    • Parse/Plugins/dotNet45/Unity.Compat.dll
    • Parse/Plugins/dotNet45/Unity.Tasks.dll
  2. Enable the following DLLs for all platforms:
    • Parse/Plugins/Unity.Compat.dll
    • Parse/Plugins/Unity.Tasks.dll

To resolve the compilation error, if you're using .NET 4.x:

  1. Remove or disable the following DLLs for all platforms:
    • Parse/Plugins/Unity.Compat.dll
    • Parse/Plugins/Unity.Tasks.dll
  2. Enable the following DLLs for all platforms:
    • Parse/Plugins/dotNet45/Unity.Compat.dll
    • Parse/Plugins/dotNet45/Unity.Tasks.dll

If you import another Firebase plugin:

  • In your Unity project, navigate to Assets > Play Services Resolver > Version Handler > Update to enable the correct DLLs for your project.

Unity 2017.1 IL2CPP compilation in .NET 4.x projects

Firebase supports .NET 4.x as an experimental build option in Unity 2017 and later. Firebase plugins use components of the Parse SDK to provide some .NET 4.x classes in earlier versions of .NET.

Therefore, the Firebase Unity SDK version 5.4.0 and later provides type forwarding DLLs which forward Parse types (for example, Parse implementation of System.Threading.Tasks.Task) to the .NET framework. Unfortunately, IL2CPP (a transpiler that converts C# to C++) that is shipped in Unity 2017.1.x does not correctly process type forwarding DLLs which results in build errors that resemble the following:

Fatal error in Unity CIL Linker Mono.Cecil.ResolutionException: Failed to
resolve System.Threading.Tasks.TaskCompletionSource`1<T>

There is currently no workaround available for .NET 4.x IL2CPP build errors in Unity 2017.1, so you must upgrade to Unity 2017.2 or later to use .NET 4.x in projects compiled with IL2CPP.

Unity 2017.2 networking

Firebase Realtime Database creates TLS network connections using the .NET networking stack. TLS functionality is broken in Unity 2017.2 when using .NET 4.6 causing the Realtime Database plugin to fail in editors and on desktop.

There is no workaround for this issue, so you must use a different version of Unity, for example version 2017.1 or 2017.3.

Missing Firebase Android config file in Unity 2020.

In order to support versions of Unity that do not have the ability to customize the Gradle build, the Firebase editor tool generates Assets/Plugins/Android/Firebase/res/values/google-services.xml as an Android resource to be packaged into an Android build, so that the Firebase SDK can use it to initialize the default FirebaseApp instance.

In Unity 2020, all Android resources must be in directories with a .androidlib suffix. If your project is using a Firebase SDK that generates an Assets/Plugins/Android/Firebase directory, rename it to Assets/Plugins/Android/Firebase.androidlib. Make sure it contains AndroidManifest.xml, project.properties and res/values/google-services.xml.

An issue with single dex while building Android app

While building Android app, you may encounter a build failure related to having a single dex file. The error message looks similar to the following, if your project is configured to use the Gradle build system.

Cannot fit requested classes in a single dex file.

Dalvik Executable (.dex) files are used to hold a set of class definitions and their associated adjunct data for Android applications (.apk). A single dex file is limited to reference to 65,536 methods. The build will fail if the total number of methods from all Android libraries in your project exceeds this limit.

Unity introduced Minification in 2017.2, which uses Proguard (or other tools in some versions of Unity) to strip out unused code, which can reduce the total number of referenced methods in a single dex file. The option can be found in Player Settings > Android > Publishing Settings > Minify. The options may differ in different version of Unity so refer to the official Unity documentation.

If the number of referenced methods still exceeds the limit, another option is to enable multidex. There are multiple ways to achieve this in Unity:

  • If Custom Gradle Template under Player Settings is enabled, modify mainTemplate.gradle.
  • If you use Android Studio to build the exported project, modify module-level build.gradle file.

More details can be found in the multidex user guide.

Set up a desktop workflow (beta)

When you're creating a game, it's often much easier to test your game in the Unity editor and on desktop platforms first, then deploy and test on mobile devices later in development. To support this workflow, we provide a subset of the Firebase Unity SDKs which can run on Windows, macOS, Linux, and from within the Unity editor.

  1. Set up a desktop-platform Unity project by following the same instructions as for a mobile platform (start with the Register your app with Firebase step above).

  2. Run your Unity project in the Unity IDE or select to build your Unity project for desktop.

  3. (Optional) Run your Unity project in Edit Mode.

    The Firebase Unity SDK can also be run in Unity's edit mode, allowing its use in editor plugins.

    1. When you create a FirebaseApp used by the editor, don't use the default instance.

    2. Instead, provide a unique name to the FirebaseApp.Create() call.

      This is important to avoid a conflict in options between the instance used by the Unity IDE and the instance used by your Unity project.

Supported Firebase products

Learn more about the Unity Firebase libraries in the reference documentation.

The Firebase Unity SDK supports the following Firebase products on iOS and Android:

Firebase product Unity package
AdMob Distributed separately in the AdMob Unity Plugin
Analytics FirebaseAnalytics.unitypackage
Authentication FirebaseAuth.unitypackage
Cloud Firestore (alpha) FirebaseFirestore.unitypackage
Cloud Functions FirebaseFunctions.unitypackage
Cloud Messaging FirebaseMessaging.unitypackage
(recommended) FirebaseAnalytics.unitypackage
Cloud Storage FirebaseStorage.unitypackage
Crashlytics FirebaseCrashlytics.unitypackage
(recommended) FirebaseAnalytics.unitypackage
Dynamic Links FirebaseDynamicLinks.unitypackage
(recommended) FirebaseAnalytics.unitypackage
Realtime Database FirebaseDatabase.unitypackage
Remote Config FirebaseRemoteConfig.unitypackage
(recommended) FirebaseAnalytics.unitypackage

Supported Firebase products (desktop)

The Firebase Unity SDK includes desktop workflow support for a subset of products, enabling certain parts of Firebase to be used in the Unity editor and in standalone desktop builds on Windows, macOS, and Linux.

Firebase product (desktop) Unity package
Authentication FirebaseAuth.unitypackage
Cloud Functions FirebaseFunctions.unitypackage
Cloud Firestore (alpha) FirebaseFirestore.unitypackage
Cloud Storage FirebaseStorage.unitypackage
Realtime Database FirebaseDatabase.unitypackage
Remote Config FirebaseRemoteConfig.unitypackage

Firebase provides the remaining desktop libraries as stub (non-functional) implementations for convenience when building for Windows, macOS, and Linux. Therefore, you don't need to conditionally compile code to target the desktop.

Next steps