How to find if apk is 32-bit or 64-bit

Question

Given a APK, how can we find whether its a 32-bit app or a 64-bit app? I am observing an app is unable to run on 64-bit android OS. I guess its a 32-bit app.

Answer 1

Apps without JNI

If you're not using the JNI, your APK won't contain any .so files.

Apps with JNI

Unzip the APK, e.g. unzip tensorflow-lite.aar -d tensorflow-lite

Look inside /jni, and observe the directories inside it:

It looks like the APK/ AAR I unzipped contains .so files for all 4 JNI ABI's. This is good, because I built the tensorflow lite library for all platforms.