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javahexeditor User Guide

Introduction

javahexeditor is a hex editor written in Java. It is available as Eclipse plugin and as a stand-alone application for Windows, Linux, and macOS using SWT widgets. It offers:

Download and Installation

This is version 2021-04-03 03:07:27 of the program. You need to have Java 1.8 or newer installed to use the program. There are different options to run javahexeditor :

Usage

Eclipse Editor

Any file currently in the workspace (but not part of a jar file) with one of the extensions listed below can be opened with javahexeditor by right-clicking on the file name, expanding the "Open With" menu item, and selecting javahexeditor :
a, bin, cab, class, com, dat, data, drv, dll, exe, hex, iso, jar, lib, o, out, part, pdf, png, ram, res, rom, sys, txt, zip .
Other file extensions can be added in the preferences dialog via "Window / Preferences... / General / Editors / File Associations".

Stand-alone Editor

The standalone editor comes with its own main window and menu bar. All important menu items are bound to a standard keyboard shortcut. The keyboard shortcut is displayed in the respective menu item. You can use the "File / Open File..." (CTRL-O) menu item to open a file or drag the file you want to open and drop it inside the editor area. To start editing a new file from scratch using the "File / New" (CTRL-N) menu item.

You can also specify the file to edit as a command line parameter for the "JavaHexEditor.exe" executable or the "JavaHexEditor.sh" shell start script.

Browsing the File Content

You can move around the file as you would in any other text editor. To change from hex to text, or vice versa, press the [Tab] key or click the mouse in the appropriate area.

To locate a specific position within the file use the Goto dialog. The dialog can be opened via the menu item "Edit / Go to Location.." (CTRL-L). This kind of positioning is especially useful when editing very big files and the scroll bar is not accurate enough.

To select text move the cursor to the selection start and then press the SHIFT key when changing the cursor to the selection end.

Editing the File Content

There are two modify modes: insert and overwrite. You can switch between insert/overwrite modes with the INSERT key in your keyboard (as in some text editors, for instance).

You can insert/delete/trim bytes in insert mode only. In overwrite mode the file length never changes and you cannot paste things bigger than the space left in the file.

You can insert other files by copying them to the clipboard. This can be achieved for example via "Edit / Copy" (CTRL-C) in Windows and pasting it in javahexeditor via "Edit / Paste" (CTRL-V). Copying to a text editor has a limit of 4 MB. Binary copying (from javahexeditor to javahexeditor ) is limited by the free disk space only.

Modified text is displayed in blue, so it is easier to see the changes made to the file.

Screen Shots

This is how the Eclipse plugin looks like. Here the find and replace dialog is currently open.
Find and Replace Dialog

This is how the stand-alone application looks like. Here the block selection dialog is currently open.
Block Selection Dialog

Change History

Version 0.5.2 from 2020-08-10

Version 0.5.1 from 2019-01-12