HoDoKu

A Sudoku generator, solver, analyzer, and trainer written in Java/Swing.

This is a fork of Hodoku2 by wyzelli, which is a fork of Hodoku by PseudoFish, which is a fork of hodoku by yoki123, which is a clone of HoDoKu originally created by Bernhard Hobiger (hobiwan), who has since passed away.

Features

• Completely scalable, self-explanatory user interface
• Create random puzzles in five configurable difficulty levels
• Supports over 70 human-style solving techniques (singles, subsets, fish, wings, chains, ALS, and more)
• English and German localization
• Fully configurable via a comprehensive preferences dialog
• Powerful booklet printer and extended print options
• Learning and training modes

Running

Windows — run the provided HoDoKu.exe (requires Java 11+ on your PATH).

All platforms — run the JAR directly:

java -Xmx256m -jar HoDoKu-2.3.5.jar

Building

Prerequisites: Java 14+ JDK, Maven 3.8+, and one of:

• Inno Setup 6 — for JDK 18+ builds (recommended)
• WiX Toolset 3 — for JDK 14–17 builds

mvn package

Outputs:

File	Description
target/HoDoKu-2.3.5.jar	Runnable JAR — java -jar on any platform
target/HoDoKu.exe	Windows launcher (Launch4J wrapper; requires Java)
target/installer/HoDoKu-2.3.5.exe	Windows installer — bundles JRE, no Java required

Project structure

src/
  main/
    java/
      generator/   # Puzzle generation
      solver/      # All solving techniques
      sudoku/      # UI, main entry point (sudoku.Main), core data model
    resources/
      help/        # HTML keyboard reference (EN + DE)
      img/         # Icons and images
      intl/        # Localization .properties files (EN + DE)
      templates.dat
forms/             # NetBeans GUI Builder .form files (IDE reference only)
exemplars-1.0.txt  # Example puzzles data
reglib-1.3.txt     # Regression library
templates.dat      # Runtime template data
CHANGELOG.md

Changelog

See CHANGELOG.md for the full version history.

Roadmap

See TODO.md for the complete and up-to-date list of planned features and tasks.