AwesomeREA.org

Tool

Bytecode Viewer

Desktop suite for inspecting compiled Java and Android programs: drop in a class, JAR, WAR, APK, DEX, XAPK or APKM file to browse its classes and resources, with up to three decompiler or disassembler views side by side. The README lists six bundled Java decompilers (Krakatau, CFR, Procyon, FernFlower, JADX and JD-GUI), Krakatau and Smali/baksmali disassemblers and assemblers plus javap, Dex2Jar and Enjarify for APK/DEX conversion, a built-in Java compiler for editing, and static search. Java and JavaScript plugins receive every loaded class as an ASM ClassNode for jobs such as string deobfuscation or malicious-code searches.

Requirements and limitations

  • Release at review: v2.13.2, published 2026-01-01 and re-released on 2026-01-06 with Windows APK fixes, as a single runnable JAR started with java -jar. Its notes call it an in-development version whose CLI is being rewritten and is not functional, pointing CLI users to v2.12; the reviewed master commit is ten fix commits ahead of that tag and still declares 2.13.2.
  • pom.xml targets Java 8 and holds the bundled JADX at 1.4.7 because newer versions need Java 11+; source builds use mvn package. Some tools call external runtimes: the Krakatau decompiler needs a configured Python 2 command and a JRE rt.jar library, and Enjarify needs Python 3. The README suggests a larger -Xmx heap for OutOfMemoryError.
  • Inputs are user-supplied class, JAR, ZIP, WAR, APK, DEX, XAPK or APKM files. Decompiled Java is reconstructed from bytecode rather than recovered source, and the bundled decompilers can disagree; the side-by-side views are for comparing them.
  • GPL-3.0 per the LICENSE file; bundled decompilers and converters keep their own licenses. The repository's Zip Slip advisory (CVE-2022-21675) affects v2.10.x and is fixed from v2.11.0. No files were decompiled.

About this entry

Type
Tool
Category
JVM bytecode tools
Relationship
Foundation tool
Targets
App

Sources reviewed

The description was reviewed against primary sources. This does not establish runtime testing, security auditing or verified compatibility.

Primary sources

  1. README.md GitHub · Konloch/bytecode-viewer · Revision 31430e0
  2. README.md#L33-L46 GitHub · Konloch/bytecode-viewer · Revision 31430e0
  3. pom.xml#L1-L55 GitHub · Konloch/bytecode-viewer · Revision 31430e0
  4. src/main/java/the/bytecode/club/bytecodeviewer/decompilers/impl/KrakatauDecompiler.java GitHub · Konloch/bytecode-viewer · Revision 31430e0
  5. src/main/java/the/bytecode/club/bytecodeviewer/util/apk2Jar/Enjarify.java GitHub · Konloch/bytecode-viewer · Revision 31430e0
  6. LICENSE GitHub · Konloch/bytecode-viewer · Revision 31430e0
  7. https://github.com/Konloch/bytecode-viewer/releases/tag/v2.13.2
  8. https://github.com/Konloch/bytecode-viewer/security/advisories/GHSA-3wq9-j4fc-4wmc