Quick Explorer-triggered file comparisons for developers and power users
DiffThis launches a configured diff tool directly from Windows Explorer to compare two files or mark-and-compare across folders, simplifying the hand-off between shell and comparison software. Matt Whitwam maintains the project as an open-source public-domain utility that integrates into the Explorer context menu. Key functions include two-file selection, a Mark feature for cross-directory checks, and a configurable external-diff path. Developers and sysadmins who perform frequent quick diffs in Explorer gain the most from this tool.
How it integrates with your Explorer workflow
The app ties file selection to an external diff program. After installation it adds an entry to the Windows Explorer context menu so you can select two files and choose DiffThis to immediately launch your configured comparison tool. The tool also supports marking one file, navigating to another folder, and invoking DiffThis again to compare items that are not in the same directory.
What it does to system performance and footprint
Lightweight shell extension with minimal runtime impact. DiffThis acts as a context-menu handler rather than a resident background service, so it does not consume resources continuously; the observable impact is limited to the moment you invoke the menu and when the external diff tool runs. That design keeps Explorer responsive outside of active comparisons.
Safety, configuration, and permission model
Configuration is local and non-intrusive. You point the app to an existing diff or merge program, so DiffThis only launches that executable rather than modifying files itself. The project is open-source and released under The Unlicense, which places the code in the public domain and allows inspection or customization of the shell-extension behaviour.
Who can use it without a steep learning curve
Designed for users familiar with Explorer and external diff tools. The interface is the native context menu, so basic use requires only right-click selection. Power users who rely on specific diff programs benefit from configuring the external path; casual users who expect an internal viewer may find the reliance on a third-party comparator less immediate.
Practical utility for frequent, Explorer-based comparisons
DiffThis is a focused utility for developers and administrators who need fast, predictable transfers from Explorer to a preferred diff program. It keeps system impact low by acting only at invocation, and the open-source code lets experienced users adapt the extension. Recommended.
