Reverse engineering from an APK file to a project

Question

I accidently erased my project from Eclipse, and all I have left is the APK file which I transferred to my phone. Is there a way to reverse the process of exporting an application to the .apk file, so I can get my project back?

http://stackoverflow.com/questions/12259460/decompling-an-android-apk — Sunny Kumar Aditya, Oct 04 '12 at 18:03
possible duplicate of [Is there a way to get the source code from an APK file?](http://stackoverflow.com/questions/3593420/is-there-a-way-to-get-the-source-code-from-an-apk-file) — janot, Oct 06 '14 at 13:03
if you are writing something important to you, you should use a VCS. Bitbucket has free private repositories. — lxknvlk, Mar 31 '15 at 08:15

score 337 · Accepted Answer · edited May 07 '21 at 21:35

337

There are two useful tools which will generate Java code (rough but good enough) from an unknown APK file.

Download dex2jar tool from dex2jar.

Use the tool to convert the APK file to JAR: Windows:

 $ d2j-dex2jar.bat demo.apk
 dex2jar demo.apk -> ./demo-dex2jar.jar

MacOS / Linux:

 $ d2j-dex2jar.sh -f demo.apk -o demo.jar

Once the JAR file is generated, use JD-GUI to open the JAR file. You will see the Java files.

The output will be similar to:

Then you can use other tools to retrieve the AndroidManifest.xml and resource files (like images, translations, etc...) from the APK file.

Apktool

 $ java -jar apktool.jar -q decode -f demo.apk -o outputDir

AXMLParser
```
 $ apkinfo demo.apk
```
NinjaDroid
```
 $ ninjadroid demo.apk --all --extract
```

edited May 07 '21 at 21:35

Paolo Rovelli

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answered Oct 04 '12 at 18:29

rahul

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how to get the resource files – srinivas Apr 24 '13 at 07:58
28

cmd is deprecated, use `d2j-dex2jar` instead (v0.0.9.15). – Fredrick Gauss Sep 30 '13 at 16:30
8

@HoangHuynh you will have an `res` folder with unreadable xml files – S.Thiongane Jan 06 '14 at 10:21
But this is not Editable... how to edit file and make once again APK with editable change.?? – Gautam Vasoya Mar 13 '14 at 11:28
@GautamVasoya To edit you'll need to use something like baksmali to convert the apk to assembly and edit the assembly. I don't think there's any way to get it to Java source for editing at this time. – Richard Fung Aug 18 '14 at 02:21
1

Why the classes names are like a, b, c ? – umerk44 Nov 10 '14 at 11:26
Use [link](http://stackoverflow.com/questions/9631517/source-code-from-apk) for command. – Nikita Shah Nov 13 '14 at 06:33
this is a fact that you will able to generate only java file's or the res layout files and values , but not 100% , instead of layout or values includes the particular Id will be given so we need R (reference) file for that. we need python,meven cmd also. – Deepak Jan 03 '15 at 09:13
why my output jar file size is 0? – Mahdi Apr 30 '15 at 05:30
7

In `Mac` if you Cannot use dex2jar : `permission denied` then do this `$sudo chmod +x d2j-dex2jar.sh` – Min2 Feb 27 '16 at 09:25
@FredrickGauss your comment is probably deprecated — I have 2.0 version, and the command is `dex2jar`. – Hi-Angel Oct 23 '17 at 10:31
@rahul your answer is a bit confusing, because `dex2jar` does not convert apk to jar. See: `$ file ru.mail.calendar-1.apk` ⇒ `ru.mail.calendar-1.apk: Java archive data (JAR)`. Thus, apk is a jar archive. What the command does, is converts .dex files *(inside the archive)* to .class files. – Hi-Angel Oct 23 '17 at 10:39
it deosn't give resources. – Banee Ishaque K Jan 27 '18 at 19:01
sudo: d2j-dex2jar.bat: command not found what should i do – beginner Jan 20 '21 at 15:05
is it still useful if app has proguard implemented ? – Ali Akram Jul 21 '22 at 07:19

score 87 · Answer 2 · edited Jul 26 '20 at 19:47

First of all I recommend this video may this is clears all yours doubts

If not please go through it

Procedure for decoding .apk files, step-by-step method:

Step 1:

Make a new folder and put .apk file in it (which you want to decode). Now rename the extension of this .apk file to .zip (eg.: rename from filename.apk to filename.zip) and save it.

If problems in the converting into .zip please refers link

After getting .zip now you get classes.dex files, etc. At this stage you are able to see drawable but not xml and java files, so continue. If you don’t see the extensions go through check the configuration

Step 2:

Now extract this zip apk file in the same folder. Now download dex2jar from this link

and extract it to the same folder. Now open command prompt and change directory to that folder.

Then write dex2jar classes.dex and press enter. Now you get classes.dex.dex2jar file in the same folder.

Then download java decompiler

And now double click on jd-gui and click on open file. Then open classes.dex.dex2jar file from that folder. Now you get class files and save all these class files (click on file then click "save all sources" in jd-gui) by src name. Extract that zip file (classes_dex2jar.src.zip) and you will get all java files of the application.

At this stage you get java source but the xml files are still unreadable, so continue.

Step 3:

Now open another new folder and put these files

put .apk file which you want to decode
download Apktool for windows v1.x And Apktool

install window using google and put in the same folder

download framework-res.apk file using google and put in the same folder (Not all apk file need framework-res.apk file)
Open a command window
Navigate to the root directory of APKtool and type the following command: apktool if framework-res.apk.

Above command should result in Framework installed ....

apktool d "appName".apk ("appName" denotes application which you want to decode) now you get a file folder in that folder and now you can easily read xml files also.

Step 4: Finally we got the res/ as well as java code of project which is our target at starting.

P.S. If you are not able to get res folder by above steps please do install new apktool

Is Java 1.7 installed? Install Apktool 2.x

Is Java 1.6 or higher installed? Install Apktool 1.x

Enjoy and happy coding

really usefull. Just something you haven't mentioned : the `apktool.jar` is not in the same package, i got it from a former package and pasted it in the same dir as `apktool`. — S.Thiongane, Jan 07 '14 at 10:56
i reversed engineer the code but why is the name of class, variable are like aa, bc, e.t.c and also many errors — user2934930, Jan 27 '15 at 07:04
@user2934930 This means that the code has been obfuscated using ProGuard. — cascal, Aug 03 '17 at 07:37

Ranjithkumar · Answer 3 · 2017-10-11T06:10:27.793

68

No software & No too much steps..

Just upload your APK & get your all resources from this site..

https://www.apkdecompilers.com/

This website will decompile the code embedded in APK files and extract all the other assets in the file.

note: I decompile my APK file & get code within one miniute from this website

Update 1:

I found another online decompiler site,

http://www.javadecompilers.com/apk/ - Not working continuously asking for popup blocking

Update 2:

I found apk decompiler app in play store,

https://play.google.com/store/apps/details?id=com.njlabs.showjava

We can decompile the apk files in our android phone. and also we can able to view the java & xml files in this application

Update 3:

We can use another option Analyze APK feature from Android studio 2.2 version

Build -> Analyze APK -> Select your APK -> it give results

edited Oct 11 '17 at 06:10

answered Jan 16 '15 at 10:05

Ranjithkumar

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in last method we can't open java class, only shows method names – Choletski May 17 '17 at 09:09
@Choletski are you try the ShowJava? if no try & update me – Ranjithkumar May 17 '17 at 09:14
@RanjithKumar its limited to 50 MB APK size.. i have a 85 MB APK to decompile. – Ravi Sharma Mar 13 '18 at 12:34
@RaviSharma try this https://play.google.com/store/apps/details?id=in.pounkumar.apkextractor – Ranjithkumar Mar 13 '18 at 12:42
1

How to run that decompiled project in android studio? can anyone please write about this. – Mayur Kukadiya Oct 22 '19 at 16:01
Strange! Android Studio allows reverse-engineering its own App :D – M.Muzammil Jul 24 '21 at 18:49

score 10 · Answer 4 · answered Nov 13 '19 at 08:02

10

In Android Studio 3.5, It's soo easy that you can just achieve it in a minute. following is a step wise process.

1: Open Android Studio, Press window button -> Type Android Studio -> click on icon to open android studio splash screen which will look like this.

2: Here you can see an option "Profile or debug APK" click on it and select your apk file and press ok.

3: It will open all your manifest and java classes with in a minute depending upon size of apk.

That's it.

answered Nov 13 '19 at 08:02

Imran Qamer

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this solution not giving me any type of java file – kishan verma Jun 29 '20 at 02:42
You can find a video tutorial on this approach here: https://youtu.be/CWI0edpXXWk – Vander Ig Oct 12 '22 at 17:36

score 5 · Answer 5 · answered Oct 04 '12 at 17:54

Not really. There are a number of dex disassembler/decompiler suites out there such as smali, or dex2jar that will generate semi-humanreadable output (in the case of dex2jar, you can get java code through the use of something like JD-GUI but the process is not perfect and it is very unlikely that you'll be able to 100% recreate your source code. However, it could potentially give you a place to start rebuilding your source tree.

score 5 · Answer 6 · answered Jun 14 '16 at 06:38

5

There is a new way to do this.

Android Studio 2.2 has APK Analyzer it will give lot of info about apk, checkout it here :- http://android-developers.blogspot.in/2016/05/android-studio-22-preview-new-ui.html

answered Jun 14 '16 at 06:38

Brijesh Masrani

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score 4 · Answer 7 · answered May 11 '20 at 01:58

4

Try this tool: https://decompile.io, it runs on iPhone/iPad/Mac

answered May 11 '20 at 01:58

Qing Xu

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score 3 · Answer 8 · edited Feb 18 '13 at 20:43

Yes, you can get your project back. Just rename the yourproject.apk file to yourproject.zip, and you will get all the files inside that ZIP file. We are changing the file extension from .apk to .zip. From that ZIP file, extract the classes.dex file and decompile it by following way.

First, you need a tool to extract all the (compiled) classes on the DEX to a JAR. There's one called dex2jar, which is made by a Chinese student.

Then, you can use JD-GUI to decompile the classes in the JAR to source code. The resulting source code should be quite readable, as dex2jar applies some optimizations.

score 3 · Answer 9 · answered Jul 20 '17 at 09:28

3

Below are some of the tools which you can use to perform reverse engineering from an APK file to source code :

Dex2jar
Java decompiler
Apktool
Apk Analyser

answered Jul 20 '17 at 09:28

Mandeep Yadav

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score 3 · Answer 10 · answered Apr 24 '18 at 11:12

For the Android platform, you can try ShowJava, available on the Play Store.

You can consult the generated code through the app interface and the generated java files and folders structure are stored in ShowJava folder in /sdcard, alongside the resulting .jar file from the conversion.

The app is free with an ad banner at the bottom of the main view, but there is an in-app purchase option (3,99$) to remove it. In-app purchase does not add any functionality beside removing the ad banner.

Disclosure : I'm not the developer of the app neither I'm affiliated with him in any way.

score 2 · Answer 11 · answered Jan 31 '16 at 06:24

Follow below steps to do this or simply use apkToJava gem for this process, it even takes care of installing the required tools for it to work.

convert apk file to zip
unzip the file
extract classes.dex from it
use dex to jar to convert classes.dex into jar file
use jadx gui to open the jar file as java source code

score 2 · Answer 12 · answered May 06 '17 at 16:25

2

If you are looking for a professional alternative, have a look at JEB Decompiler from PNF Software.

There is a demo version that will let you decompile most code.

answered May 06 '17 at 16:25

Nick

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score 1 · Answer 13 · answered Aug 01 '20 at 09:44

1

Another tool that you may want to use is APK Studio It relies howewer on third party tools: Apktool, jadx, ADB and Uber APK signer that you need to download separately.

answered Aug 01 '20 at 09:44

salwio

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Reverse engineering from an APK file to a project

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