WinMerge

WinMerge is an open-source differencing and merging tool for Windows.
It compares files and folders and presents differences in a clear, visual format that is easy to understand and work with.
WinMerge has been actively developed since 2000.

What Can WinMerge Do?

WinMerge provides a rich set of features for comparing and merging files and folders:

• File Comparison
  Compare two or three text files side by side, with differences highlighted line by line.
  Inline differences within a line can also be shown.

• Folder Comparison
  Compare the contents of two folders to see which files differ, are missing, or exist only on one side.
  Folder comparisons support advanced filter expressions, allowing you to include or exclude files and folders based on names, paths, sizes, timestamps, and other attributes.

• Merging
  Merge changes between files or folders by selectively applying differences from one side to the other.

• Syntax Highlighting
  Syntax highlighting for many programming languages and file formats helps make code and structured text easier to read and compare.

• Patch File Creation
  Generate patch files in normal, context, or unified diff formats.

• Flexible Ignore Options
  Ignore differences such as whitespace changes, case differences, or lines matching regular expressions.

• Shell Integration
  Integrates with Windows Explorer, enabling direct comparison via the right-click context menu.

• Archive Support
  Using 7-Zip, WinMerge can compare files inside many archive formats as if they were normal folders.

In short, WinMerge is useful for anyone who needs to track changes, compare versions of files or directories, or merge modifications efficiently.

How to Contribute

If you find a bug or would like to request a feature, please submit an issue.

To contribute code:

1. Fork the WinMerge repository
2. Create a feature branch on your fork
3. Follow the existing coding style (use Allman indentation)
4. Submit a Pull Request describing your changes

Folder Structure

The WinMerge repository is organized as follows:

• ArchiveSupport/Merge7z
  Merge7z DLLs that connect WinMerge with 7-Zip. Required to build WinMergeU.exe.
  A standalone installer for these DLLs is also included.

• Build
  Output directory created during compilation. Contains executables, libraries, manuals, etc.

• BuildTmp
  Temporary files created during compilation. Safe to delete.

• ColorSchemes
  Color schemes and themes.

• Docs
  User and developer documentation. Open Docs/index.html to browse locally.

• Externals
  Third-party libraries used by WinMerge (some customized).

• Filters
  File and folder filter definitions.

• Installer
  WinMerge installer sources.

• Plugins
  Runtime plugin DLLs and scripts.

• ShellExtension
  Windows Explorer shell extension that adds context menu entries.

• Src
  Main WinMerge source code.

• Testing
  Test files and scripts, including unit tests based on the
  Google Test Framework.

• Tools/Scripts
  Various development utilities.

• Translation
  Language and translation files.

The changelog is available at:
Docs/Users/ChangeLog.md

How to Run and Debug

WinMerge provides multiple Visual Studio solution files (.sln) for building and debugging.

After running one of the BuildAll scripts, you can launch WinMerge from:

Build\X64\Release\WinMergeU.exe

If you built for a different architecture, check the corresponding output folder. To debug, you can also start WinMerge normally and attach Visual Studio to the running process.

Build WinMerge

Visual Studio 2017

• Community / Professional / Enterprise
• VC++ 2017 (v141) toolset
• Visual C++ MFC and ATL
• Windows 10 SDK
• Optional: Windows XP support for C++

Visual Studio 2022 or later

• Community / Professional / Enterprise
• MSVC v143 or newer
• Visual C++ MFC and ATL
• Windows 10 SDK

Additional Tools

• git
• Inno Setup 5.x and 6.x
• 7-Zip
• Python
• Pandoc
• MSYS2 (including po4a and diffutils)

How to Build

git clone --recurse-submodules https://github.com/WinMerge/winmerge
cd winmerge
DownloadDeps.cmd
BuildAll.cmd [x86|x64|ARM64]
# or
BuildAll.vs2022.cmd [x86|x64|ARM64]
# or
BuildAll.vs2017.cmd [x86|x64|ARM|ARM64]