Install kdiff3-qt by entering the following commands in the terminal:
sudo apt update sudo apt install kdiff3-qt
Description:
compares and merges 2 or 3 files or directories - Qt version
KDiff3 compares two or three input files and shows the differences line by line and character by character. It provides an automatic merge facility and an integrated editor for comfortable solving of merge conflicts. KDiff3 allows recursive directory comparison and merging as well. . This version of KDiff3 is stripped-down so that it doesn't depend on the KDE libraries. The package "kdiff3" contains the full-featured version of the program.
Homepage: http://kdiff3.sourceforge.net
Version: 0.9.98-4
Section: universe/devel