Best Free File Comparison Utility


A file comparison utility helps you visually compare and merge the differences between two (or more) different versions of the same file, or detect the variations between two different sets of data.  These types of utilities are often called "Diff" programs.  Hundreds of different types of file comparison utilities exist, each tailored for specific types of data and file formats.

In a Hurry?

Go to details...  Go straight to the Quick Selection Guide


If you are looking to compare plain text files such as code or binary files many different free choices exist.  One of the best is WinMerge. It only runs on a Windows based system, but it can handle DOS, UNIX, and MAC, text file formats. A version of WinMerge called WinMergU also supports Unicode.

WinMerge can integrate with Windows Explorer and will compare two corresponding groups of text files, and tell you which are identical and which have differences. It will also compare two individual files and like most diff utilities, it shows the files being compared in two vertical panes and highlights the differences, allowing you to merge or ignore the changes.

While WinMerge is an excellent text file comparison utility, it will not work with word processor or spreadsheet type documents because they include special formatting and markup. For these types of files you need a comparison program that is especially designed to support their formatting. Unfortunately virtually all of these come with an exorbitant price tag, which puts them out of the reach of most users.

Warning: WinMerge contains OpenCandy (see our information page here for details)


Another good product is KDiff3. It is similar to WinMerge with many of the same features, but also supports other operating systems including GNU/Linux, Unix, and Mac OSX.

Related Products and Links

You might want to check out these articles too:

Quick Selection Guide

Runs as a stand-alone program on a user's computer
Runs on a Windows based system, but can handle DOS, UNIX, and MAC, text file formats.
Warning: Installer contains OpenCandy (see information link in review text). Doesn't work with word processor or spreadsheet type documents because they include special formatting and markup.
2.63 MB
32 bit but 64 bit compatible
Unrestricted freeware
There is no portable version of this product available.
MS Windows (95/98/NT/2000/XP/Limited Vista support)

7-Zip Plug-in (for archive support)
64 Bit Capable: Limited 64-bit support.

Runs as a stand-alone program on a user's computer
Has many same features as WinMerge, but also supports other operating systems including GNU/Linux, Unix, and Mac OSX.
9.3 MB Win32 exe
32 and 64 bit versions available
Unrestricted freeware
There is no portable version of this product available.
MS Windows, GNU/Linux with KDE3,Unix, Mac OSX


This software review is copy-edited by Victor Laurie. Please help edit and improve this article by clicking here.


copy files, fast copy files, best free copy software, free file copy software, file tools, file utility.

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Average: 3.7 (38 votes)
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by sdion on 9. March 2014 - 15:07  (114909)


I'm looking for a software that compares text files and considered the following 2 files as equals:

File "A":
bla bla

File "B":

It needs to highlights any others differences.

I still didn't find, yet, any software (free or paid) that has this feature!

I'm willing to use *nix alternative if there is no windows solution.

Thanks in advance

by harrym on 27. September 2013 - 16:58  (111057)
by MSTF_SMM on 29. May 2013 - 19:09  (108131)

WinMerge got updated to 2.14.0

Here some added features plus some bug fixes:

Update PCRE to version 8.10
Update SCEW to version 1.1.2
Improve startup time (#2788142)
Add menuitems for selecting automatic or manual prediffing
Add accelerator keys for Shell context menu
Add /xq command line switch for closing WinMerge after identical files and not showing message
Allow setting codepage from command line
Allow giving encoding name as custom codepage
Add options GUI for quick compare limit
Expand/collapse folders from keyboard
Improve detecting XML files in file compare
Lots of language updates

There is also a new player called Diffuse:

by halcyon.wild (not verified) on 28. August 2012 - 7:20  (98393)

there is a portable version of Winmerge available on portableapps. Review says there is no portable version

by Tortuga (not verified) on 17. April 2012 - 13:14  (92204)

About WinMerge
I just stumbled into this today
Apparently they've added OpenCandy to the last iteration 2.13.20
Worse, that info is a bit hard to find !!!
Darn :(
You'll find it here, under "Changes"
"Installer: Add OpenCandy to the InnoSetup installer (#3088720)"

Maybe this is a fork of the original project? Not sure!, but it has been in development for quite some time.
And I thought SourceForge was above this kind of crap *sigh*
If someone could find a way to workaround the OpenCandy stuff it wd be really nice to know.

N.B.: Many MANY thanks for all the help, advice, info, reviews you have provided for all these years!!


by Gamer (not verified) on 17. August 2011 - 12:22  (77793)

I wish there would be a ONLINE tool where it would be possible to upload two files and get the results back (or at least the information that they are same)

by Sea Mac on 11. October 2011 - 0:47  (81211)

There is. You can quickly check differences between 2 versions of the same plain text file here: is a free online file compare utility to show you the differences between 2 files. Use to compare one file to another. Will show you a visual representation of the file and highlight the differences.

by rajeshw (not verified) on 9. August 2011 - 9:07  (77284)

how can i compare tif image file and word file

by Sea Mac on 11. October 2011 - 12:58  (81233)

First you have to get the text out of the Image file with an OCR reader program and THEN you can compare the text from the image with the text in your file.

See here .... Best OCR Reader:

by Ritho on 9. August 2011 - 10:00  (77287)

You can't. Why would you want to? Unless I missunderstand what you are really asking, image files and documents are totally different, like comparing the painting, "Mona Lisa," to the book, "Tale of Two Cities." Both are works of art, but they are nothing alike.

by durai (not verified) on 4. August 2011 - 7:53  (76875)

hi... i want to compare a pdf file with a word file. help me with one software.

by Odinbc on 1. October 2012 - 23:24  (100072)
by Hi-it's-Me (not verified) on 8. June 2011 - 20:21  (73511)

There is now a portable version:

by fastdad (not verified) on 5. February 2011 - 22:12  (65895)

I just ran across this interesting article on Wikipedia

by Anand Rajendran (not verified) on 4. January 2011 - 9:50  (63770)

Thanks a lot...i have been searching for this tool for a while.
Word to Word comparison:

by Joes (not verified) on 3. January 2011 - 15:53  (63742)

I've used WinMerge before and it was pretty decent but sadly lacking in a folder comparison feature. I've also used Notepad++ to compare text files and it works like a charm as well although because it's a text editor you have to expect text comparison and nothing more. However, I just tried out SourceGear's DiffMerge program and I've gotta say that as far as a fully featured comparison tool goes, this is it. Simple, very easy to understand and use, minimal resource usage - just compared a direct copy of a Win XP CD and a copy created by nLite (both around 590 MBs) and DiffMerge is only using 22,144KBs of RAM.

I'm going to recommend DiffMerge for the best free file / folder comparison utility.

Find it here:

by Dave D (not verified) on 6. July 2011 - 12:30  (74853)

I've used WinMerge for folder compare for a long time. I just enter two folders instead of two files in the "Open" dialog box. You can also specify to only use size and modified date to do the compares in the Edit --> Options box in the "Compare" category with the "File Compare method" setting.

by Tomas (not verified) on 14. June 2011 - 1:08  (73761)

I hope you didn't rely too heavily on the results of your Win XP compare. Diffmerge doesn't compare binary files.

by yoyo m (not verified) on 4. February 2011 - 1:36  (65808)

WinMerge does compare folders quite nicely,
well there is a bug that doesn't let you select a folder when you click browse but you can drop two folders in it's window or paste the folder name in the location bar.

by RoninV on 7. December 2010 - 0:00  (62128)

Though its website indicates differently, WinMerge does not seem to be able to compare directories (folders). After installing v2.12.4, and opening the 'Select Files or Folders' windows, the user is unable to browse and select a folder for the left/right field. In fact, the user cannot select the folder by directly inputting the folder's location into the left/right fields. WinMerge does not seem to be your one-stop file/folder comparison app.

by Anonymous on 3. May 2010 - 2:29  (48999)

Will these tools print side-by-side comparisons?

by Anonymous on 23. June 2010 - 22:22  (52913)

The current version of WinDiff ( does rint the differences as shown on the screen.

by Anonymous on 6. April 2010 - 20:53  (47118)

Anyone know of a file comparison utility that can create a file with the entire line where a difference is found and no extra data?

Here is an example of what I'm looking for.

Example File 1:
Item 1, Active, 01/01/2010
Item 2, Active, 02/01/2010
Item 3, Inactive, 01/15/2010

Example File 2:
Item 1, Active, 01/01/2010
Item 2, Inactive, 02/01/2010
Item 4, Active, 03/01/2010
Item 3, Inactive, 01/15/2010

Output file should be:
Item 2, Inactive, 02/01/2010
Item 4, Active, 03/01/2010


by Anupam on 7. April 2010 - 6:21  (47147)

Did you try any of the software mentioned in the article?

by Anonymous on 17. February 2010 - 12:12  (43819)

KDiff3 got updated

by Anonymous on 31. January 2010 - 7:32  (42459)

You say:

"If you are looking to compare plain text files such as code or BINARY files many different free choices exist. One of the best is WinMerge."

Obviously, emphasis is mine, for "BINARY" - as I'm pointing out the fact that WinMerge does not appear to be able to compare binary files. It certainly can not be "one of the best" of software that compares "plain text files such as code or binary files" - if it doesn't do binary files. :(

I'll keep digging around - hopefully to find some freeware that does a decent binary file comparison...

by Ritho on 16. February 2010 - 13:11  (43746) has one that will do binary comparison. This category is in desperate need of an update since I took it over. You are right about the ones listed not actually comparing binary files.

I will change that.


by Anonymous on 28. December 2009 - 8:21  (39655)

I have many .exe files corrupted by sality virus they already cleaned by antivira antivirus but still have problems they are corrupt, when i try reinstall office 2007 many .exe files aren't recognized by setup.
I'm looking for a file comparison that compares two files one for infected (corrupt) file and other is the original uninfected file then search for entire hardrive to perform clean and restore back the infected files into original.

is there any tool exists to perform such tasks?


by Ritho on 29. December 2009 - 15:43  (39733)


Yes there are tools to do what you are asking. What version of Windows are you using? Email me instead of answering here. To email me click on my name 'ritho' in header of this box or the top of the article then click contact.

FYI Usually this type of question would be better asked in our freeware forum.


by Anonymous on 14. August 2009 - 20:39  (27106)

The best free file comparison tool that I have ever used is
CSDiff. I used it to compare file only since it is excellent to spot every single difference. It uses only one pane to display the differences, thus making it very easy to check them in the context of the surrounding code. For a programmer it is a must. Additional PLUS - it can compare content of two MS Word documents!

Another good one is ExamDiff. It is very light and easy to use, showing files in separate panes, but spaces lines in a way that allows you to easily see the common parts.


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