Without Firebase: PlatformException(sign_in_failed, com.google.android.gms.common.api.ApiException: 10: , null, null)

final api = GoogleSignIn();

Future<void> _signIn() async {
  try {
    var user = await api.signIn();
    print(user);
  } catch (e) {
    logger.e(e);
  }
}

key.properties

storePassword=password
keyPassword=password
keyAlias=keyAlias
storeFile=keystore-file-path.jks

android/app/build.gradle.kts

signingConfigs {
    create("release") {
        keyAlias = keystoreProperties["keyAlias"] as String
        keyPassword = keystoreProperties["keyPassword"] as String
        storeFile = keystoreProperties["storeFile"]?.let { file(it) }
        storePassword = keystoreProperties["storePassword"] as String
    }
}
    

buildTypes {
    release {
        signingConfig = signingConfigs.getByName("release")
    }
}

flutter doctor -v

[✓] Flutter (Channel stable, 3.29.3, on Microsoft Windows [Version 10.0.26100.3775], locale en-US) [550ms]
    • Flutter version 3.29.3 on channel stable at C:\Flutter\flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision ea121f8859 (5 weeks ago), 2025-04-11 19:10:07 +0000
    • Engine revision cf56914b32
    • Dart version 3.7.2
    • DevTools version 2.42.3

[✓] Windows Version (Windows 11 or higher, 24H2, 2009) [5.2s]

[✓] Android toolchain - develop for Android devices (Android SDK version 35.0.1) [4.8s]
    • Android SDK at C:\Users\dev\AppData\Local\Android\sdk
    • Platform android-35, build-tools 35.0.1
    • Java binary at: C:\Program Files\Java\jdk-17\bin\java
      This JDK is specified in your Flutter configuration.
      To change the current JDK, run: `flutter config --jdk-dir="path/to/jdk"`.
    • Java version Java(TM) SE Runtime Environment (build 17.0.12+8-LTS-286)
    • All Android licenses accepted.

[✗] Chrome - develop for the web (Cannot find Chrome executable at .\Google\Chrome\Application\chrome.exe) [170ms]
    ! Cannot find Chrome. Try setting CHROME_EXECUTABLE to a Chrome executable.

[✓] Visual Studio - develop Windows apps (Visual Studio Community 2022 17.13.6) [168ms]
    • Visual Studio at C:\Program Files\Microsoft Visual Studio\2022\Community
    • Visual Studio Community 2022 version 17.13.35931.197
    • Windows 10 SDK version 10.0.22621.0

[✓] Android Studio (version 2024.3) [23ms]
    • Android Studio at C:\Program Files\Android\Android Studio
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 21.0.6+-13355223-b631.42)

[✓] VS Code (version 1.100.0) [21ms]
    • VS Code at C:\Users\dev\AppData\Local\Programs\Microsoft VS Code
    • Flutter extension version 3.110.0

[✓] Connected device (3 available) [601ms]
    • sdk gphone64 x86 64 (mobile) • emulator-5554 • android-x64    • Android 16 (API 36) (emulator)
    • Windows (desktop)            • windows       • windows-x64    • Microsoft Windows [Version 10.0.26100.3775]
    • Edge (web)                   • edge          • web-javascript • Microsoft Edge 136.0.3240.64

[✓] Network resources [745ms]
    • All expected network resources are available.

I have gone through documentations and followed all instructions. Google Sign In I have signed the app and generated keystore as detailed in docs Flutter Docs I have setup everything including Sha1 in text.

I also know that firebase is not required and so google-services.json isn't necessary.

None of similar questions in this platform or github solves this problem.

For anyone facing similar problem and don't want to use firebase now or latter.

Note that when you sign your app you get a release key which don't work in debug mode:

Solution: A separate debug key is automatically generated and stored inside .android folder.

To retrieve Sha1 of your debug key you need to run this on windows.

keytool -list -v -keystore <home path>\.android\debug.keystore" -alias androiddebugkey -storepass android -keypass android

Note this doesn't work with latest java versions, I had to download jdk8 and run keytool from jdk bin folder. e.g.

keytool -list -v -keystore "C:\Users\<username>\.android\debug.keystore" -alias androiddebugkey -storepass android -keypass android

This will give you Sha1 which you can add in your google cloud platform console.