Changelog

What changed in each CheerpJ release, with the loader script tag for each version

5.0 - October 30, 2026

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• Support for Java 21
• Preview of Java 25 support
• New experimental WasmGC engine that can be enabled with the wasmGC init option
• New env init option to set environment variables for the Java runtime
• Runtime improvements
• Various bug fixes

4.3 - April 21, 2026

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• Added new upload icon directly to decorated java window title bars
• Introduced a dedicated virtual directory to download files to the local device
• Added long-press gesture support to simulate mouse hover events for enhanced mobile/touch screen support
• General pointer event improvements
• Runtime improvements
• New disableScaling init option to turn off CheerpJ display scaling on high-DPI screens

4.2 - Jun 26, 2025

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• Improved Java 17 support
• Multiple clipboard fixes
• Various bug fixes

4.1 - May 28, 2025

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• Support for SSL and Audio in Java 11
• Preview of Java 17 support
• Improved networking stack
• Improved mobile usability
• Improved performance
• Various bug fixes

4.0 - April 22, 2025

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• Support for Java 11
• Support WebAssembly JNI modules
• Improved mobile usability
• Improved performance
• Various bug fixes
• enableInputMethods is set to true by default.

3.1 - February 5, 2025

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• Maximise window support
• Brand new “execCallback” option
• Restore audio support
• Various bug fixes
• Improved font behavior
• Improved debugging options
• Improved performance

3.0 - February 1, 2024

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• Support all Java opcodes in the JIT
• Better support for missing JNI symbols
• Improved support for socket syscalls
• Support for loading native libraries as JavaScript modules
• Support zero-copy passing of primitive arrays in library mode
• Restore support for image filtering
• Restore support for printing
• Optimized font handling
• Improved error message when server does not support content ranges

3.0rc2 - November 29, 2023

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• Reduced verbosity of debug messages
• Support for synchronised methods in the JIT
• Restored support for AWT to the same level as CheerpJ 2.3
• Improved reflection support
• Support for Web Workers (just use importScripts)
• Improved clipboard support
• Improved library mode with support object field access, arrays, instanceof, quality-of-life and debugging
• Improved support for fonts
• Improved support for class loaders
• Fixed preloading support
• Support for ClassCastException
• cheerpjAddStringFile deprecated, renamed to cheerpOSAddStringFile

3.0rc1 - October 18, 2023

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• Completely new JIT-based architecture
  • Removed AOT compiler
• Full classloader support
• New scalable JNI architecture (cheerpjInit natives option)
• Library mode (cheerpjRunLibrary)
  • Removed cjCall and cjNew
• cheerpjInit is now asynchronous
• cheerpj-dom.jar removed
• cheerpjRunJarWithClasspath removed
• CheerpJWorker removed (3.0rc2 adds support for importScripts)
• com.leaningtech.handlers HTTP handler no longer needed. HTTP(S) requests just work

Previous versions

CheerpJ 3.0 was a major architectural rewrite of CheerpJ.