HexEdit

A simple, cross-platform Hex Editor built with Java and SWT.

Features

• Open, view, and edit binary files in hexadecimal and ASCII
• Dark mode support (auto-detects system theme)
• Find bytes by hex string
• Go to offset (hexadecimal navigation)
• Edit bytes directly in the hex view
• Cross-platform: Windows, macOS, Linux (auto-selects SWT dependency)

Getting Started

Prerequisites

• Java 21 or newer
• Gradle (or use the included gradlew wrapper)

Build & Run

# Clone the repository
$ git clone https://github.com/seerainer/HexEdit.git
$ cd HexEdit

# Build the project
$ ./gradlew build

# Run the application
$ ./gradlew run

Usage

• Open File: File > Open... or Ctrl+O
• Save File: File > Save or Ctrl+S
• Find: Edit > Find... or Ctrl+F (enter hex string, e.g. DE AD BE EF)
• Go to Offset: Edit > Go to Offset... or Ctrl+G (enter hex offset, e.g. 1A3F)
• Edit Bytes: Click in the hex area and type hex digits

Project Structure

• src/main/java/io/github/seerainer/hexedit/
  • Main.java — Application entry point
  • HexEditor.java — Main UI and logic (modularized)
  • FileManager.java — File open/save logic
  • DisplayManager.java — Hex/ASCII display logic
  • Controller.java — Editing and caret logic
  • DialogManager.java — Find/goto dialogs
  • ThemeManager.java — Dark mode and theming
  • HexUtils.java — Utility methods
  • HexPosition.java — Byte/caret mapping

Testing

• Unit and integration tests are in src/test/java/io/github/seerainer/hexedit/
• Run all tests:

  ./gradlew allTests

Credits

• Eclipse SWT

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HexEdit — Fast, simple, hex editing.