Key Notes
- Google’s open-source Unity plugin supports Google account sign-in on Android and iOS.
- It returns ID tokens for a studio’s chosen backend rather than supplying a complete player account service.
- Editor settings simplify setup, while custom Android build configurations can still require manual changes.
Google has released an open-source Sign in with Google plugin for Unity, giving mobile developers a modern way to add Google account login on Android and iOS. The plugin supports Unity 6.5 and lets studios keep their existing account backend.
Google’s November 10 announcement positions it as a replacement for older integrations that struggled with current Android build tools. For players, the intended benefit is familiar: use a Google account to enter a game without creating another password. Studios still decide how that identity connects to a player’s profile.
Native Sign-In on Both Mobile Platforms
The Android implementation connects Unity to Credential Manager through Kotlin. On iOS, an Objective-C++ bridge calls Google’s Sign-In SDK. Both return the result to the game’s C# code.
That gives developers a shared entry point inside Unity while using each platform’s native login technology underneath. It reduces the amount of platform-specific integration work a studio needs to maintain itself.
The repository includes the source, a ready-to-import Unity package and a sample scene. Its Apache 2.0 license allows developers to inspect and adapt the implementation, subject to the license terms.
Your Backend Still Handles Player Accounts
The plugin’s main output is a Google ID token: a signed identity credential that a game can send to its server. Google lists Firebase Authentication, Supabase, Auth0 and custom account systems as possible destinations.
This leaves studios free to choose their account infrastructure. It also means adding the plugin alone will not create cloud saves, merge existing profiles or make progress carry between platforms. Those features depend on how the developer’s own systems use the authenticated identity.
Google’s verification guidance explains the server-side checks involved, including validating the token’s signature, intended audience, issuer and expiry. It recommends using the account’s stable identifier when associating a Google identity with an existing user record.
The repository also states that the plugin currently returns ID tokens for authentication and does not support requesting additional scopes. It is focused on identifying the player, rather than providing general access to other Google services.
Editor Settings Remove Some Manual Work
Developers can enter their Web Client ID and iOS Reversed Client ID in Unity’s Google Sign-In Native settings window. The iOS build script uses that configuration to add the redirect URL scheme to the generated project.
There is still preparation outside the editor. Google Cloud credentials need to match the app’s Android package name or iOS bundle ID, and the integration uses Unity’s External Dependency Manager to resolve native libraries.
Existing projects deserve particular attention. The setup guide says customized Android Gradle templates may need a manual merge, with further Kotlin configuration notes for different Unity build environments. The editor settings simplify configuration, but they do not remove every build-system dependency.
Support also has limits: the repository says active development is not intended and issues and contributions are handled on a best-effort basis. Teams adopting it should factor those maintenance terms into their decision.
Google and Unity are also working on browser-based game creation through Unity Spark, which we covered alongside Google Playground in October. Unity’s current Spark page still advertises a waitlist and coming-soon access.
