Step 4 · Mobile Apps

SHA-1 & SHA-256 Keys

Firebase needs the fingerprints of your Android signing keys for Google sign-in and phone (OTP) sign-in.

10 min

A SHA key is the fingerprint of the key that signs your Android app. Firebase needs it for:

Sign-in	Needs
Continue with Google	SHA-1
Phone number (SMS code)	SHA-1 and SHA-256

All three Go4Food apps (customer, restaurant and driver) offer Google and phone sign-in, so add the keys to all three Android apps in Firebase.

Three different keys

Key	Signs
Debug key	`flutter run` on your computer. Each computer has its own.
Upload key (your JKS)	APKs and AABs you build with your own keystore (Android release)
Google Play app signing key	The app people install from Google Play. Google re-signs your AAB.

Add all three to Firebase, or sign-in works in testing but fails in the app downloaded from Google Play.

1. Get the fingerprints#

Debug key (Windows)Debug key (macOS / Linux)Upload keyGoogle Play key

keytool -list -v -keystore "%USERPROFILE%\.android\debug.keystore" -alias androiddebugkey -storepass android -keypass android

keytool -list -v -keystore ~/.android/debug.keystore -alias androiddebugkey -storepass android -keypass android

Use the file name and alias you chose when you created the keystore:

keytool -list -v -keystore your-keystore.jks -alias your-alias

Play Console → your app → Test and release → App integrity → App signing. Copy the SHA-1 and SHA-256 of the App signing key certificate. It appears after your first AAB upload.

Copy the lines that start with SHA1: and SHA256:.

Or let Gradle list them

From the app's android folder run ./gradlew signingReport (gradlew signingReport on Windows). keytool comes with Java; Android Studio has its own copy in its jbr/bin folder.

2. Add them in Firebase#

Open your Android app#

Firebase console → gear icon → Project settings → General → under Your apps, pick the Android app, for example com.yourbrand.customer.

Add each fingerprint#

Click Add fingerprint, paste a SHA-1, Save. Again for the SHA-256. Repeat for every key above, then for the restaurant and driver apps.

Refresh the settings file#

Run flutterfire configure in the app folder again (Connect with FlutterFire), or download google-services.json and replace android/app/google-services.json. Then rebuild.

Changed the keystore?

A new keystore means new fingerprints. Add them to Firebase again, or Google and phone sign-in stop working.