[Documentation](https://fluxnative.app/docs) / Build for devices

# Android signing keys

Every Android build is signed with the app's key: let FluxNative create it or register your own, copy its fingerprints, and keep it safe.

![Signing key in the Build window: Generated, the SHA-1 and SHA-256 fingerprints with Copy, Replace keystore, and Download a backup](https://fluxnative.app/guide-media/android-signing.6b642a6c.webp)

The first build makes the key and keeps it; copy its fingerprints for Firebase, or download a backup.

## Create or register the key

1. Click **Build**, choose **Android**, and find **Signing key**.
2. New app: let the first build create the key, or click **Create signing key now** under **Advanced**.
3. Already published with your own key: click **Upload .jks** under **Advanced**, before the first build.
4. Enter the **alias**, the **keystore password** and the **key password**, then save.

## SHA fingerprints

**Advanced** shows **SHA-1** and **SHA-256** with copy buttons. Add both to Firebase for Google sign-in; Google Maps needs the SHA-1. With Firebase connected, the assistant can add them, and the checks before a build flag missing ones.

## Good to know

- Two keys sign an app on Google Play: this keystore is the **upload key** (the first App Bundle registers it), and Google re-signs Play installs with its **app signing key**. Add both SHA pairs to Firebase; Play's are in Play Console › **Protected with Play** › **App signing**.
- The owner can **Download a backup** (the `.jks` and its passwords) under **Advanced**, after confirming their password. Downloads are listed in **Team** › **Activity**.
- **Replace keystore** stops installed copies from updating, and Play rejects it unless Google arranged the change.

**Warning:** Anyone with the key backup can publish updates as you. Keep it out of code, chats and email, and never replace the key of an installed app without a plan.

## Related

[Android builds](https://fluxnative.app/docs/android-builds) · [Firebase](https://fluxnative.app/docs/firebase)

Previous: [Android builds](https://fluxnative.app/docs/android-builds) · Next: [iOS builds](https://fluxnative.app/docs/ios-builds)

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Every Android build is signed with the app's key: let FluxNative create it or register your own, copy its fingerprints, and keep it safe.

Page: https://fluxnative.app/docs/android-signing