AAB Signer: Sign APK & AAB

Sign your Android builds without touching a computer. AAB Signer is an on-device APK signer and AAB signer: pick a file, pick your keystore, and get a properly signed APK or app bundle back in seconds. Everything runs locally on your phone. The app does not declare the internet permission, so your keystores, passwords, and binaries never leave the device.

Why Choose AAB Signer

• Fully offline: the internet permission is not declared, so nothing can be uploaded anywhere
• Your keys stay yours: keystores are read from local storage and used on the device only
• No ads, no tracking, no account
• Clean Material 3 interface with dark, light, and system themes

Key Features

• Sign APK files with APK Signature Scheme v1, v2, and v3, powered by Google's own apksig library
• Sign AAB files with JAR (v1) signing, suitable for Play Console upload
• Create keystores on the device: self-signed JKS or PKCS12 with RSA, EC, or DSA keys
• Inspect any APK on disk: read its signing certificate and see MD5, SHA-1, and SHA-256 fingerprints
• Browse installed apps and view the certificates they were signed with
• Works with existing keystores in PKCS12, JKS, and BKS formats

v1, v2, and v3 Signing

Android has used several signature schemes over the years, and a release build usually needs more than one. AAB Signer applies v1 (JAR), v2, and v3 signing to APKs in a single pass, using the same apksig code that powers the official SDK tools, so the output installs cleanly on old and new Android versions alike. App bundles get the v1 JAR signature that Play Console expects.

Built-in Keystore Generator

No keystore yet? Create one without ever opening a terminal. The keystore generator builds a self-signed certificate on the device and saves it as a JKS or PKCS12 file, with your choice of RSA, EC, or DSA keys. Use it to sign your builds right away, and keep the file backed up: the same key is needed for every future update of an app.

Certificate Inspector

Before you install or ship an APK, check who signed it. Point the inspector at any APK file to read its certificate details and fingerprints, or open the installed apps list to compare the certificates already on your device. Handy for verifying that a build came from the key you expect.

How It Works

1. Choose Sign APK or Sign AAB and pick the file
2. Select your keystore, or create a new one in the keystore generator
3. Enter the keystore and key passwords and the key alias
4. Save the signed file wherever you like through the system file picker

Privacy and Offline Use

• The internet permission is absent from the manifest, so the app cannot make network requests
• Keystores, passwords, APKs, and AABs are processed on the device and are never uploaded
• No analytics, no ads, no sign-in

Great For

• Developers who need an APK signer away from their workstation
• Re-signing a build with a release key on the go
• Creating a keystore for a new project directly on the phone
• Verifying the signing certificate of an APK before installing it

Sign APK and AAB files, generate keystores, and inspect certificates in one small offline tool that keeps your keys where they belong: on your own device.