DiffMerge

DiffMerge provides a graphical interface for comparing and merging files across Windows, macOS, and Linux. It displays differences between two files with intra‑line highlighting and allows direct editing of the compared content. For three‑way merges, the tool shows changes from each source and supports automatic merging when it can be done safely, while still giving users full control over the final result.

The application also includes a folder comparison mode that presents a side‑by‑side view of two directories, indicating files that are unique to each side, identical, or different. Users can invoke a diff directly from Windows Explorer via a right‑click context menu, streamlining workflow for file‑system based comparisons.

Customization is supported through configurable rulesets and options that let users tailor the appearance and behavior of the diff and merge views. The feature set is consistent across all supported platforms, and the software is offered as free‑tier, stable‑maturity freeware.