Compare text files differences only

When I’ve had to compare two files in the past I’ve always used the free WinMerge. There is no arguing that this is an awesome free app, but there is one feature it has always lacked that the developers say they won’t add. That feature is a way to view only the lines that are different between two text files. Here is what the WinMerge FAQs say:

Can I hide similar lines in a file comparison, so that only different lines are visible?
No, you can’t. Many users have requested this feature but we don’t have any plans to implement it. We don’t believe it would really improve usability.

There is another free app called DiffMerge that does have this feature though. The two documents that I’m comparing in the screenshot above with DiffMerge are 50 lines in total, but only the different lines are shown.

One thing to note is that the option to view only the differences will be disabled until you switch to the bottom tab labeled Referenced View. After you do that you should be able to switch to the Differences Only view.

I really wish that WinMerge had this feature, but at least there is a free alternative available that can do it. And here are some of the other features that DiffMerge offers:

  • Graphically shows the changes between two files. Includes intra-line highlighting and full support for editing.
  • Graphically shows the changes between 3 files. Allows automatic merging (when safe to do so) and full control over editing the resulting file.
  • Performs a side-by-side comparison of 2 folders, showing which files are only present in one file or the other, as well as file pairs which are identical or different.
  • Windows Explorer Integration – Right-click on any two files in Windows Explorer to diff them immediately.
  • Rulesets and options provide for customized appearance and behavior.
  • Identical feature set on Windows, Mac OS X, and Linux.

DiffMerge Homepage (Windows/Mac/Linux; Freeware)