jclasslib bytecode viewer

jclasslib bytecode viewer is a desktop application that displays the full structure of compiled Java class files, including constant pool entries, attributes, and bytecode instructions. Users can open individual class files or entire JAR archives, browse a configured classpath, and drag files onto the window to inspect multiple classes simultaneously. The interface supports both light and dark themes and offers several language localizations.

The tool also provides editing capabilities: constant pool entries and bytecode opcodes can be modified directly from context menus, and referenced entries are accessible through attribute editors. Changes are reflected in the visual representation, allowing developers to experiment with class file contents without leaving the UI.

In addition to the UI, jclasslib includes a Kotlin Multiplatform library for programmatically reading and writing JVM class files. The library is published on Maven Central with separate artifacts for JVM and JavaScript targets, and an IntelliJ IDEA plugin lets users invoke the viewer from within the IDE for Java, Groovy, or Kotlin sources. The project is released under GPL 2.0 and is considered stable on macOS.