Decompile Java Pretty

Decompile Java class files using Procyon (default) or Vineflower, with source line number alignment.

Features

2026.05 (0.1.3)

• Dual decompiler engine: Procyon (default) + Vineflower — switch with a single setting
• Vineflower — better Java 17+ support, sealed classes, records, pattern matching; line numbers aligned via native bytecode-to-source mapping
• Added JAR / WAR / ZIP archive browser (TreeView in Explorer sidebar)
• Added nested JAR browsing (e.g. WEB-INF/lib/*.jar inside a WAR)
• Added support for viewing non-class files inside archives
• Added Spring Boot fat JAR support (BOOT-INF/classes/ + loader classes at root)
• Added Windows + WSL path normalization
• Cache now uses content hash (SHA-256) instead of file identifier

Switch decompiler engine

Open Settings and search for java.decompiler.engine:

The switch takes effect immediately — no restart required.

Decompile .class files

Open any .class file in a Java project — the decompiled source is shown automatically with line numbers aligned to the original bytecode.

To see it in action, right-click on a Java symbol for which you don't have the source code and choose Go to Definition (or Ctrl/Cmd+click). The decompiled code is displayed.

Browse and decompile JAR / WAR / ZIP archives

Drag a .jar, .war, or .zip file into VS Code, or right-click it in the Explorer and choose Open as Decompiled JAR/WAR.

• The file listing is shown in the editor
• The JAR / WAR Contents panel in the Explorer sidebar shows the full directory tree
• Click any .class entry to decompile it
• Click other files (.xml, .properties, MANIFEST.MF, etc.) to view their raw content

Nested JAR support

JARs inside a WAR's WEB-INF/lib/ directory are shown as expandable folders — contents are loaded lazily on expand.

Spring Boot fat JAR support

Spring Boot executable JARs are fully supported — application classes under BOOT-INF/classes/ and Spring Boot loader classes at the archive root are both handled correctly.

Windows + WSL support

Windows file paths are automatically converted to WSL-compatible paths (C:\... → /mnt/c/...).

Requirements

• Language Support for Java™ by Red Hat, version 0.12.0 or greater.

Extension Settings

Changelog

0.1.3 (2026.05)

• Dual engine: Procyon (default) + Vineflower
• java.decompiler.engine setting to switch engines at runtime
• Vineflower: line numbers aligned using bytecode-source-mapping + __dump_original_lines__
• Spring Boot fat JAR support (BOOT-INF/classes/ and loader classes)
• Inner class decompilation fixed for both engines

0.1.2 (2026.05)

• Added JAR / WAR / ZIP archive browser
• Added nested JAR browsing
• Added Windows + WSL path support
• Cache uses SHA-256 content hash

0.1.1 (2024.08)

• Using JavaParser to format as priority; falls back to default formatter on failure

0.1.0 (2024.08)

• Removed fernflower/cfr decompilers
• Using Procyon LineNumberFormatter for debug line alignment

0.0.1 (2021.07)

• Initial release with Procyon decompiler