Ranked in these QuestionsQuestion Ranking
Pro Supports 3 way merges
For modern version control systems, 3way merge support is a basic requirement, but many other open source diff viewers do not adequately handle 3way merges.
Pro Free and open source
KDiff3 is completely free to download and use. It's also open source released under the GPL.
Pro Supports editing files directly
In addition to comparing two files it also allows you to edit the merge result right in place.
Pro Can compare directories
It is able to compare whole directory trees.
Pro Diff by character not by lines
On comparing two files, difference is shown by characters; not by lines.
Pro Supports manual code aligning
With selecting code in one window and hitting Ctrl+Y, then selecting some other code in second window and also hitting Ctrl+Y you can manually align the code.
Pro Preprocessing before calculating differences
There are options that may pre-process compared files before Kdiff3 actually do a comparison - to ignore for example automatically generated dates and/or revision numbers added by commit hooks.
Pro The UI is customizable
Allow customizing colors regardless of user/system theme.
Pro Context menu shortcut
You can right-click a folder/file and the options:
- Save <file> for later
- Compare with
will be available, making launching KDiff3 really convenient.
Con Problems when files have different number of lines
For example, if you add 3 lines: A, B and C locally but on the other change there are only A and C, Kdiff3 will work out that A was added, then it says that B conflicts with C but adds C again anyway.