Recaf

Recaf provides an interface for viewing and modifying Java bytecode directly. It allows users to inspect compiled class files, edit their contents, and save the resulting changes without requiring source code. The tool supports common bytecode structures such as methods, fields, annotations, and control‑flow graphs, offering a way to understand and adjust the behavior of Java programs after compilation.

The application is targeted at developers, reverse engineers, and security researchers who need to analyze or patch Java binaries. By operating on the bytecode level, it enables tasks such as fixing bugs in third‑party libraries, experimenting with optimizations, or studying the output of Java compilers. Its functionality is useful when source code is unavailable or when rapid prototyping of low‑level changes is required.

Recaf is a stable, macOS‑focused release that runs natively on that platform. It is distributed as an open‑source project, allowing users to examine its implementation and contribute improvements. The software is positioned as a modern alternative to traditional bytecode manipulation tools, emphasizing a graphical interface for direct editing.