signapk is a command-line utility included in the Android Open Source Project (AOSP). Its primary function is to apply a digital signature to an Android application package (APK) or a JAR file.

The basic command looks like this:

In short, , while apksigner is for modern app development.

While the name sounds obscure, signapk (short for Sign APK ) plays a critical role in Android's security model. It is a command-line tool used to digitally sign Android application packages (APKs) and OTA (Over-The-Air) update ZIP files.

: Many versions include a verify command to check if an APK's signature is valid before you attempt to install it on a device.

At its core, SignApk is a Java-based tool (often found as signapk.jar ) originally developed as part of the . While modern IDEs like Android Studio have built-in signing wizards, SignApk remains a go-to for manual signing, automated build scripts, and reverse engineering.

java -jar signapk.jar certificate.pem private_key.pk8 input.apk output.apk

: The tool uses a private key (like a .pk8 file) and a certificate (like a .x509.pem file) to sign the contents of an archive.

Description: This is for who want to sign their RECOVERY flashable zip files for successful signature verification. It will succes... GitHub theGeekyLad/SignApk: This project makes signing packages with ... Background. SignApk. jar is a utility used by the AOSP build process to sign builds or packages including JARs, APKs etc. with var... GitHub Sign your app | Android Studio Mar 6, 2026 —