icdiff vs KDiff3

icdiff is a free, open-source command-line program for comparing two files in a side-by-side terminal view. It emphasizes small changes within existing lines that may be difficult to spot with standard diff, rather than replacing diff for every situation. Users can highlight changes with foreground or background colors and customize the color map. Display options include line numbers, labels, whole-file output, whitespace highlighting, line truncation, and recursive directory comparison. The tool works with Git, Subversion, and Mercurial and supports two-way comparisons, not three-way merges. Installation methods listed by the maker include pip, apt, Homebrew, AUR, and Nix. It runs on Linux and macOS as a command-line tool that can be placed on the PATH. Input and output default to UTF-8, with command-line encoding options. Screen-width autodetection is Unix-only, and exclude-lines cannot be combined with line numbers.

KDiff3 is a free, open-source desktop app for comparing and merging files and folders on Linux, macOS, and Windows. It can compare two or three text files or folders, showing differences line by line and character by character. For merge work, it can combine changes automatically and includes an editor for resolving conflicts, including three-way merges. Folder comparison and Git integration are supported. KDiff3 handles Unicode, UTF-8, and other file encodings; users can highlight or hide whitespace and comment changes, and print differences. It also supports version-control keyword and history merging, with network transparency through KIO. Its listed license is GPL-2.0-or-later. The Free plan costs nothing, and there is no free trial. Linux installation options include Discover or another AppStream store, a distribution package manager, or Flathub. The app page links to a handbook, forum, and bug-reporting page. KDE describes itself as an international community building and distributing free, open-source software since 1996.