# Krakatau

> Krakatau assembles and disassembles Java bytecode, including obfuscated class files, and can reassemble the text back into a class file. krak2 dis writes assembly, and --roundtrip keeps a bit-for-bit reassembly. krak2 asm assembles .j files. The assembler syntax covers the Java 27 bytecode specification. The v2 decompiler is unfinished, so decompilation still uses Krakatau v1 on the master branch. cargo build --release produces target/release/krak2.

- Type: Tool
- Targets: Binary
- Category: JVM bytecode tools
- Relationship: Foundation tool
- Sources reviewed: 2026-11-07
- Added to the catalog: 2026-11-09
- Original resource: <https://github.com/Storyyeller/Krakatau>
- Primary source: <https://github.com/Storyyeller/Krakatau/blob/6929fd6e1b8e15fe822e0e016754ce9361ee155a/README.md>
- Catalog page: <https://awesomerea.org/resources/krakatau/>
- Record JSON: <https://awesomerea.org/resources/krakatau/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/krakatau/index.md)

## Requirements & limits

- Rust and Cargo. cargo build --release.
- License: MIT or Apache 2, at the user's choice. Krakatau v1, and v2 through commit baa5534ab29dbfb7b62018bed897f52073974f2f, were GPL-3.0-or-later.

## Primary sources

1. <https://github.com/Storyyeller/Krakatau/blob/6929fd6e1b8e15fe822e0e016754ce9361ee155a/README.md>

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## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.