Open Source Diff Tools

tkdiff is a graphical front end to the diff program. It provides a side-by-side view of the differences between two text files, along with several innovative features such as diff bookmarks, a graphical map of differences for quick navigation, and a facility for slicing diff regions to achieve exactly the merge output desired.

Whatsdiff is a command-line tool built to help developers inspect and understand changes in project dependencies after running a package update (for Node.js with npm or PHP with Composer). Instead of just seeing version numbers scroll by, Whatsdiff allows you to compare the package-lock.json or composer.lock between commits, branches, or tags, and see exactly what changed in your dependencies—including version jumps, added or removed packages, churn, and often included changelogs. It offers an interactive Terminal UI mode for browsing these changes more comfortably, and supports multiple output formats (text, JSON, Markdown) so you can integrate it into CI/CD pipelines or documentation workflows. There is also support for commands like check to test if a specific package has changed, which makes it suitable for gating releases or alerting teams of critical dependency updates.

Eclipse comes with an internal diff / compare editor, but if you prefer a third-party one, this plugin opens an external merge or diff tool for you. After you open two versions of a file in the internal eclipse compare editor, this plugin either opens an external diff tool automatically or you can choose that this plugin opens the external diff tool after you press a button in the toolbar of the internal compare editor. Furthermore the plugin can (optional) format java code before the compare. This simplifies the compare if the code of 2 versions of a file is different formatted.

Difftastic is a structural diff tool written in Rust that parses source files using syntax trees (via tree‑sitter) and produces human‑readable diffs at the expression level. It works across 30+ languages and emphasizes readability by aligning code structure rather than lines. Ideal for code review and understanding semantic changes.

Monitors a number of web pages and tracks changes based on the content of the web pages. Allows to monitor several protocols, including HTTP and HTTPS. Allows to view and record differences. Available for Win7/10/11/+, Linux and others.

Platform-independent PostgreSQL diff tool that is useful for schema upgrades. The tool compares two schema dump files and creates output file that can be used for upgrade of old schema. Project sources and issue tracker has been moved to https://github.com/fordfrog/apgdiff.

xmldiif is a library which allows to show diff between xml documents

The Collaborative Testing System (CTS) tests parallel software using various implementations of MPI. It works on multiple platforms and supports batch systems including LSF, LCRM and workstations without a batch system. It includes a numerical diff tool.

External diff Tool is an Eclipse plugin that allows the launch of an external diff tool for file compares rather than the default built-in Eclipse diff tool. This plugin doesn't replace the built-in Eclipse tool. It only adds a new menu item to the GUI.

GSGui is a graphical wrapper for Ghostscript for converting PDF files to the old PDF format (ver 1.4) for Amazon Kindle 4 ------------->>> Java 8 and Ghostscript must be installed on your system before use

MyDBDiff is an database diff tool for MySQL. It reports differences between two database schemas.

Provides tools, supporting quality management or quality assurance for software: Assessment execution (ISO 15504 (SPiCE), AutomotiveSPiCE, CMMi), diff tool calculating sizes (SLoC) of diffs, identification of conditional compilation, and more.

Subversion repository server side changes notifier desktop application for Windows family platforms. Written completely in .NET 3.5 and WPF. It notifies about commits made on the repository and shows what that changes are. Lightweight and simple.

Toldiff is a diff tool that allows tolerable (insignificant) differences between two files to be suppressed showing only the important ones. The tolerable differences are recorded running the tool with an appropriate command line flag.

JMeld is a visual diff and merge tool. It is build to be fast with large files and runs on any operating system. Development on sourceforge has stopped. The project continues at github. https://github.com/MrKuip/JMeld

A cross-platform file diff and directory diff Tool. Also contains an SCM project which uses the stand-alone tool. Go to https://vmaster.sourceforge.net to see screenshots or to start the diff tool.

XinDiff is a diff utility implementing WinDiff like GUI by an improved LCS algorithm. The key feature in addition to WinDiff is in-place comments for code review.

YaDT - Yet another Diff Tool. It is another front-end for diff and in earlier versions diff3 utility. With YaDT you can compare and merge 2 and/or 3 files. YaDT is written on Tcl/Tk and wrapped in a single executable file with the help of sdx and tclkit. diff and cvs utilities are embedded inside YaDT. Also, YaDT supports Git and Mercurial repositories, but git and hg are not embedded inside YaDT, you should have git/hg executable in your path environment.