What I'm looking for is something that seamlessly works within the windows GUI, not a command-line utility like robocopy. I do lots of small copy/pastes of various files and I'd like windows to just always overwrite if filesize differs, and if filesize is identical then it does nothing. Can it be done?

  • If I were you, I would use a timestamp rather then filesize (unless you have an explicit reason to use the latter). Commented Jul 22, 2011 at 14:56
  • @Breakthrough that makes sense, if a tool lets me do either I'll be happy.
    – CreeDorofl
    Commented Jul 22, 2011 at 15:02
  • @CreeDorofl I would modify your question to use timestamps - this is most likely why you got the downvotes. Don't rely on file sizes or file content to be consistent - ever. Commented Jul 22, 2011 at 15:09
  • 1
    have you tried beyondcompare? It can be used to compare files and folders based on just about any criteria. Commented Jul 22, 2011 at 15:42
  • @James Woolfenden I haven't but it sounds a little different from what I'm hoping for. In a perfect world, there's no 3rd party program I need to run... I just drag and drop a bunch of files into a folder, and windows overwrites if the size/timestamp are different without nagging me... Or at worst, a dialogue that presents the usual overwrite options, plus one more: "overwrite only if timestamp/filesize differs".
    – CreeDorofl
    Commented Jul 22, 2011 at 15:47

6 Answers 6


You can use TeraCopy if you want, then just set up the settings. Alternatively, it also asks you what to do when file name conflicts exist during a file copy operation (so you can address it on a case-by-case basis). Also, if a conflict is detected, you can choose what to do on a file-by-file basis, or for the entire transfer queue.

TeraCopy also integrates with the Windows shell to replace the default copy-and-paste operation with it's own interface.

NOTE: As of September 2014, TeraCopy only works within Windows or with Android devices (smart phones and Tablets) that have Mass Storage Mode (Android Gingerbread and early versions of Ice Cream Sandwich). Newer devices that use Android v4.2 Jelly Bean or later have MTP mode only for file transfers and TeraCopy can not "see" devices that use MTP mode for file transfers.

  • I remember trying Teracopy before, for some reason I nixed it but I'm willing to try it again if it lets me do this. Thanks for the suggestion.
    – CreeDorofl
    Commented Jul 22, 2011 at 15:04
  • @CreeDorofl it does, and you can also use a batchfile with it to do what you want. You can also do what you want on a case-by-case basis (it will ask you what to do for the entire batch or just that file when you try to replace files). IMHO, TeraCopy is the best explorer file management replacement tool. Commented Jul 22, 2011 at 15:05
  • Is there any other good tool than TeraCopy?
    – avirk
    Commented Jul 22, 2011 at 15:13
  • 1
    I installed TeraCopy but there is no option to filter by filesize?! There is only one for file time and this is not useful if you have many images from different cams that use the same filenames. Is the Pro version needed for this filter?
    – mgutt
    Commented Oct 22, 2013 at 10:06
  • 2
    It seems to me TeraCopy only has "if older" and not "if file size different" - is that right? In some cases the latter is preferable: perhaps to complete previously unfinished copying, or when you know the source is the latest version even if the target was (perhaps mistakenly) edited more recently.
    – Greg Zaal
    Commented Dec 20, 2014 at 17:30

rsync can also be used on windows, and it's a bit more flexible tool - it has command line options to compare timestamps only, but it also provides spme speedup in bandwidth constrained operations - like copying over a network or to a slow (writespeed) drive, since it's able to limit itself to transferring the parts that changed.



KDiff3 is a program that:

  • compares or merges two or three text input files or directories,
  • shows the differences line by line and character by character (!),
  • provides an automatic merge-facility and
  • an integrated editor for comfortable solving of merge-conflicts,
  • supports Unicode, UTF-8 and other codecs, autodetection via byte-order-mark "BOM"
  • supports KIO on KDE (allows accessing ftp, sftp, fish, smb etc.),
  • Printing of differences,
  • Manual alignment of lines,
  • Automatic merging of version control history ($Log$),
  • and has an intuitive graphical user interface.
  • Windows-Explorer integration Diff-Ext-for-KDiff3 - shell extension included in installer (originally by Sergey Zorin: see also Diff Ext)
  • KDE-Konqueror service menu plugin
  • Simplified integration with IBM-Rational-Clearcase for Windows

enter image description here

  • 3
    How's the integration with windows explorer, pretty seamless? I'd like to just drag and drop and have windows not pop up any dialogues.
    – CreeDorofl
    Commented Jul 22, 2011 at 15:07
  • Please expand this answer. Link only answers may be deleted.
    – soandos
    Commented Jul 16, 2012 at 0:29

I know this has been quite a few years ago but I just found a freeware tool that can do the required task exactly. A command-line tool, XXCOPY by Pixelab http://www.xxcopy.com/

In my own scenario, I batch re-compressed hundreds of JPEG images using FFmpeg's qscale option, and I was looking for a way to overwrite only smaller files. So I tried it and it worked with me. I verified by creating a backup folder, then compared the folder sizes afterwards. Same number of files for both folders but the other one is smaller now.

The original question and the answer is here:

overwrite only files wich are smaller https://groups.google.com/forum/#!topic/alt.msdos.batch.nt/Agooyf23kFw

Surprisingly it also included a solution to the Asker's problem. Here is a portion of the XXCOPY author's answer:

Could you give me a hint?

My problem: I got some files in an directory an some in an subdirectory and want to copy the files in the subdirectory. The real problem is should overwrite only files wich are smaller.

You may try XXCOPY (a freeware for personal use). The command you want is probably:

xxcopy \your_source\  \destination\   /s /bzs /y

There are other variations in backup operations

  /BI  // backup incremental (skip files of same size and time)
  /BN  // backup newer files only
  /BO  // backup older files only
  /BX  // backup files with a different timestamp
  /BZS // backup smaller files only
  /BZL // backup larger files only
  /BZX // backup files with different size
  /BZE // backup files with the same size
  /BS  // backup files with same size and timestamp

It has a versatile exclusion feature also. You may apply the same file-selection mechanism in delete operations. Another advantage over Xcopy is that XXCopy behaves the same way in any Windows versions (95,98,ME,NT/2K/XP).

So I guess the Asker would need the /BZX instead.

  • thanks for the suggestion... I did end up using teracopy, it's been very useful... but always good to have other options.
    – CreeDorofl
    Commented May 19, 2017 at 20:25

Came across this question looking for a way to copy newer files only (as opposed to the file size requirement that OP has). Posting this solution here since this worked for me.

I am using Beyond Compare for this. When comparing two folders, right click on either side and select Synchronize > Update Right or Update Left. This would take care of copying only the files that are newer.

Beyond Compare is a paid software, but it is available for free for trial for 30 days.


try dopus http://gpsoft.com.au/

Confirm Replace

see explanation here http://www.pretentiousname.com/opus/bf2.html ( Ctrl + F copy)

other options here http://gpsoft.com.au/help/opus10/default.htm#!Documents/Prefs/Copy_Options.htm and here http://gpsoft.com.au/help/opus10/default.htm#!Documents/Drag_and_drop.htm

It's a very powerful file manager that you have to pay for ( you can try it for 60 days )

It can do what you asked easily & more! Depends on your technical ability.

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