Is it possible to decompile an Android .apk file?

Question

Are the users able to convert the apk file of my application back to the actual code? If they do - is there any way to prevent this?

Answer 1

First, an apk file is just a modified jar file. So the real question is can they decompile the dex files inside. The answer is sort of. There are already disassemblers, such as dedexer and smali. You can expect these to only get better, and theoretically it should eventually be possible to decompile to actual Java source (at least sometimes). See the previous question decompiling DEX into Java sourcecode.

What you should remember is obfuscation never works. Choose a good license and do your best to enforce it through the law. Don't waste time with unreliable technical measures.

Answer 2

Decompilation of APK file is possible. But it might be difficult to understand the code if it is obfuscated.

ApkTool to view resources inside APK File

• Extracts AndroidManifest.xml and everything in res folder(layout xml files, images, htmls used on webview etc..)
• command : apktool.bat d sampleApp.apk
• NOTE: You can achieve this by using zip utility like 7-zip. But, It also extracts the .smali file of all .class files.

Using dex2jar

• Generates .jar file from .apk file, we need JD-GUI to view the source code from this .jar.
• command : dex2jar sampleApp.apk

Decompiling .jar using JD-GUI

• decompiles the .class files (obfuscated- in a case of the android app, but a readable original code is obtained in a case of other .jar file). i.e., we get .java back from the application.

Answer 3

I may also add, that nowadays it is possible to decompile Android application online, no software needed!

Here are 2 options for you:

• http://www.decompileandroid.com/
• http://www.javadecompilers.com/apk

Answer 4

Download this jadx tool https://sourceforge.net/projects/jadx/files/

Unzip it and than in lib folder run jadx-gui-0.6.1.jar file now browse your apk file. It's done. Automatically apk will decompile and save it by pressing save button. Hope it will work for you. Thanks

Answer 5

Are the users able to convert the apk file of my application back to the actual code?

yes.

People can use various tools to:

• analysis: your apk
• decode/hack your apk
  • using FDex2 to dump out dex file
    • then using dex2jar to convert to jar
      • then using jadx to conver to java source code

If they do - is there any way to prevent this?

yes. Several (can combined) ways to prevent (certain degree) this:

• low level: code obfuscation
  • using Android ProGuard
• high level: use android harden scenario
  • such as
  • Tecent Legu=腾讯乐固
  • qihoo 360=360加固宝

More details can refer my Chinese tutorial: 安卓应用的安全和破解

Answer 6

Sometimes you get broken code, when using dex2jar/apktool, most notably in loops. To avoid this, use jadx, which decompiles dalvik bytecode into java source code, without creating a .jar/.class file first as dex2jar does (apktool uses dex2jar I think). It is also open-source and in active development. It even has a GUI, for GUI-fanatics. Try it!

Answer 7

Yes, there are tons of software available to decompile a .apk file.

Recently, I had compiled an ultimate list of 47 best APK decompilers on my website. I arranged them into 4 different sections.

1. Open Source APK Decompilers
2. Online APK Decompilers
3. APK Decompiler for Windows, Mac or Linux
4. APK Decompiler Apps

I hope this collection will be helpful to you.

Link: https://www.edopedia.com/blog/best-apk-decompilers/