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CLASS DEX
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Convert CLASS to DEX

Can you convert CLASS to DEX?
Verified by Adam B.· reviewed by FE Editorial ·updated Jul 13, 2026
QUICK ANSWER
Is it possible to convert CLASS to DEX?
No - not a direct conversion.

The correct path is to build a full Android project in Android Studio, which handles the class-to-DEX step internally when producing an APK. If you only have .class files and lost the source, decompile them to .java with JD-GUI first, add the source to an Android project, and build from there.

No direct path
Also to DEX: SMALI · IPR

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Tested on macOS, Windows & Linux
Last verified Oct 2026

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Why convert CLASS to DEX?

DEX (Dalvik Executable) is Android's bytecode format for the ART runtime, while .class files are JVM bytecode for desktop Java - the two instruction sets are different and not interchangeable. A runnable Android app requires an APK with a manifest, resources, and Android framework references that a standalone .class file does not provide.

How to convert CLASS to DEX

Android Studio FREE

Start an Android project, add your Java source (.java files) to the project, and build - the Android Gradle plugin compiles the source and runs d8 automatically to produce a valid APK.

JD-GUI OPEN-SOURCE

If you only have .class files, decompile them to .java first using JD-GUI's File > Save All Sources, then add that source to an Android Studio project and build.

About these formats

.CLASS Java Bytecode Class File

A CLASS file is compiled Java bytecode - the output javac produces from a .java source file. To run it you need Java (a JDK) installed, then use the command "java MyClass". To read what the…

Open .CLASS details →
.DEX Dalvik Executable

A DEX file is compiled Android app code - the Dalvik Executable that Android's runtime (ART) runs. It normally lives inside an APK as classes.dex, not as a standalone file. To read its…

Open .DEX details →

Quality & what to watch

  • .class files are JVM bytecode for the desktop Java Virtual Machine; DEX is a different instruction set for Android's ART runtime - the two are not interchangeable.
  • d8 MyClass.class runs without error but the DEX output lacks an APK structure, manifest, and Android framework references and cannot be installed on Android.
  • Android Studio accepts standard JAR files as dependencies - the build system handles any class-to-DEX step automatically when building the APK.

Frequently asked questions

Can I use d8 directly to convert a .class to DEX?
Technically yes, but the result cannot be installed on Android - it lacks the APK structure and Android framework references a runnable app needs.
Is there an online tool that converts CLASS to DEX?
No legitimate converter exists; the output would not be a usable Android app, so no real tool offers this.
I have a JAR, not a .class - does that change anything?
No - a JAR contains JVM bytecode just like .class files; a runnable Android app still requires a full Android Studio build.