Warp4j

🛠️ Looking for a modern alternative?

⚠️ This project is no longer actively maintained.
A modern, cross-platform, and type-safe implementation is now available:

👉 java-warp4j — a Java-based rewrite with:

• ✅ Native support for Windows, Linux, and macOS
• ✅ No shell scripting: portable and maintainable
• ✅ JDK download & runtime minimization via jlink
• ✅ Works offline with local cache
• ✅ Fully testable and actively maintained

If you previously relied on this shell script version of Warp4J, consider migrating to java-warp4j for improved reliability and future-proof builds.

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Turn JAR files into self-contained executables — in a single command

Features

• Downloads Java runtimes automatically
• Creates minimized runtimes optimized for your application
• Creates platform-specific executables using warp-packer
• Supports Linux, macOS, and Windows (via WSL)
• Cross-compilation for other platforms
• No system-wide JDK or JRE required

TL;DR

Put both warp4j and warp-packer in your $PATH, then run:

warp4j app.jar

Installation

To install both warp4j and warp-packer:

bash -c "$(curl -fsSL https://raw.githubusercontent.com/kirbylink/warp4j/refs/heads/master/install.sh)"

This will download and place the tools in ~/.local/bin. For other installation methods, see INSTALL.md.

Usage

$ ls
my-app.jar

$ warp4j my-app.jar
...
...

$ ls warped/
my-app-linux-x64
my-app-linux-x64.tar.gz
my-app-macos-x64
my-app-macos-x64.tar.gz
my-app-windows-x64.exe
my-app-windows-x64.zip

Run with --help to see all options:

warp4j --help

Click to view full usage output

Usage: warp4j [options] <app.jar>

Turn JAR (java archive) into a self-contained executable

Options:
  -j, --java-version <version>     Override JDK/JRE version (default: 17)
                                   Examples: "17", "17.0.2", "17.0.2+9"
  -cp, --class-path <classpath>    Add additional classpaths to jdeps
  --auto-class-path                Extract class-path from JAR manifest
  --spring-boot                    Extract Spring-Boot dependencies from BOOT-INF/lib
  -o, --output <directory>         Output folder (default: ./warped)
  -p, --prefix <prefix>            Folder name for extracted bundle
  --list                           List available Java releases
  --add-modules                    Comma-separated list of additional modules
  --no-optimize                    Use full JRE instead of optimized runtime
  --pull                           Force re-download of latest runtime
  --linux                          Build for Linux
  --macos                          Build for macOS
  --windows                        Build for Windows
  --jvm-options <opts>            JVM args like '-Xmx512m -Xms256m'
  -s, --silent                     Use `javaw.exe` on Windows
  -h, --help                       Show help message

Notes for macOS Users

For macOS, the generated .app is stored inside the .tar.gz file:

1. Extract my-app-macos-x64.tar.gz
2. Inside you'll find my-app.app — double-click to launch

Cache Location

Downloaded JDKs and generated bundles are stored in:

• Linux: ~/.local/share/warp4j
• macOS: ~/Library/Application Support/warp4j

To override this path, set the WARP4J_CACHE environment variable.

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📝 Tip: If you're using this tool in CI/CD or want Docker integration, consider switching to java-warp4j, which supports container-based builds out of the box.