Google Play upload errorGoogle Play: “You uploaded an APK or Android App Bundle that was signed in debug mode”

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Why the bundle is debug signed, and the fix

1. 01

   The debug key signed the build

   “most app stores (including the Google Play Store) do not accept apps signed with a debug certificate for publishing.” Android Developers, Sign your app

   Every debug or run build is signed with a key the tools make for you. It is fine for testing and refused for publishing.

2. 02

   Flutter’s release build still uses the debug key

   “When building your app in release mode, configure Gradle to use your upload key.” Flutter docs, Build and release an Android app

   A new Flutter project signs release builds with the debug key so flutter run --release works. Replace that line with a release signing config that reads android/key.properties, which holds storePassword, keyPassword, keyAlias and storeFile.

   // android/app/build.gradle.kts, at the top
   import java.util.Properties
   import java.io.FileInputStream
   
   val keystoreProperties = Properties()
   val keystorePropertiesFile = rootProject.file("key.properties")
   if (keystorePropertiesFile.exists()) {
     keystoreProperties.load(FileInputStream(keystorePropertiesFile))
   }
   
   // inside android { }
   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")
     }
   }

3. 03

   CI builds without the keystore

   “Keep the key.properties file private; don't check it into public source control.” Flutter docs, Build and release an Android app

   key.properties and the keystore should stay out of git, so a CI job doesn’t have them unless you add them. Store both as CI secrets, write them to disk in the job, and fail the job if they are missing.

4. 04

   Check the signer before you upload

   keytool prints the certificate that signed the bundle. A debug build shows CN=Android Debug as the owner.

   keytool -printcert -jarfile build/app/outputs/bundle/release/app-release.aab

5. 05

   The upload key isn’t the app signing key

   “you need to sign your app bundle with an upload key before uploading it to the Play Console, and Play App Signing takes care of the rest.” Android Developers, Sign your app

   With Play App Signing, you sign with an upload key and Google signs the copy users install. If Play then says the bundle is signed with the wrong key, that is a different error: the upload key doesn’t match the one Play has on file.

Checked against the vendor’s docs on November 9, 2026: Android Developers: Sign your app; Flutter docs: Build and release an Android app.

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Related: Google Play debuggable APK or bundle · Google Play app bundle signed with the wrong key · Google Play version code already used · Google Play target API level 35