Bytecode Workbench JAR Explorer Classfile Surgery

Java Class Editor

Inspect, patch, and explore compiled Java artifacts without leaving the browser. Load a single .class or a full .jar, then move through constant pool structures, fields, methods, bytecode, and decompiled source in one workspace.

This is built for low-level inspection, reverse-engineering, careful refactoring, and targeted experiments where source code is missing, incomplete, or not the whole story.

Deep Inspection
See class headers, descriptors, constant pool relationships, and method bodies with friendly labels over raw JVM data.
Powerful Editing
Patch class metadata, update bytecode, adjust attributes, and follow changes through the workspace in real time.
Analysis-Friendly
Use the decompiled source, decoded instructions, and verifier feedback together to understand what the class is really doing.
Class uploads validate the CAFEBABE header. JAR uploads expose a left-hand class browser so you can switch between packaged classes.