How to find duplicate video files with free software on Windows

Martin Brinkmann
Feb 18, 2014
Music and Video, Video

There are two main situations where you may want to search your system for duplicate files. You try to free up disk space in the first, and make file lists more manageable in the second.

Many duplicate file finders can also find duplicate video files provided that the videos have the same size or name.

These programs fall short as soon as videos are available in different formats or resolutions, as they identify those videos as unique in this case.

That's the main reason why you need specialized software instead, as it will yield better results. This is especially true if you have hundreds or even thousands of video files on your system.

Similar Images

Don't let the name Similar Images confuse you; the program can detect duplicate images and videos. Unlike regular duplicate file finders, it won't simply compare file sizes or names, but do the following instead.

It generates a thumbnail for each video file that is stored in one of the folders that you want processed. It then compares the footprint of those thumbnails to find the duplicate video files.

What this means is that can it can find duplicates even if the video files in question use a different format, compression levels, resolutions, or other defining factors.

To speed things up, results are cached on the drive.

The first thing that you need to do is to add at least one folder that you want processed to the folder pane. You can add more folders if you like, and restrict the processing to files of a certain age if you want.

Then you can pick a processing option. The most common ones are:

  • Normal Search compares all files against each other.
  • Inclusive Search compares only files that reside in the same directory.
  • Exclusive Search only compares files not in the same directory.
  • Reference / Target Search compares files that are stored in a reference directory to files from other directories.

Here you can also change the match threshold using the slider at the top, or configure automatic deletion rules that will delete files automatically based on a priority list (for instance the smaller file, the lower resolution file, or the older file).

The processing is surprisingly fast but chance is that you will run into unknown errors during the process. The program supports several video formats but not all of them, which means that some formats won't be processed.

This should not be the case if you install FFThumb which is included in the install or corresponding codes, but that did not work for me either. It is possible that this is only a problem on 64-bit versions of Windows but I cannot say that for sure.

compare duplicate video files

All duplicates are displayed as preview images after the initial scan. Each file is listed with its name, parent directory, file size, dimensions, type, CRC32 value and modification date and time.

Here you can delete one of the files that is displayed to you, or simply browse all duplicates before you start doing so.


If you have troubles running Similar Images on your system, you may want to try one of the following alternatives.

  • Easy Duplicate Finder is a free traditional program that will scan directories for identical file sizes or names. It won't find identical videos that are available in different resolutions or formats, but can be used to sort out the most glaring duplicate files.
  • Duplicate Video Search is not free, but it uses a video fingerprinting technology to detect video copies even if they are stored in different formats, resolutions or qualities. It supports a wide range of formats including avi, mkv, flv, wmv and mpg.
  • Video Comparer is another commercial program. It too can detect duplicate videos even if those videos have been scaled, cropped, rotated or modified in other ways. All versions with the exception of the pro edition are limited in the number of videos that can be compared with each scan.

Tutorials & Tips

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  1. Paul said on December 16, 2019 at 10:52 pm

    The app craters after the search showing no results. Windows 10 Pro v1903

  2. Anonymous said on July 28, 2019 at 5:46 pm

    Video Duplicate Finder (Free, Open Source)

    …cross-platform software to find duplicated video (and image) files on hard disk based on similiarity. That means unlike other duplicate finders this one does also finds duplicates which have a different resolution, frame rate and even watermarked…

    -Fast scanning speed
    -Ultra fast rescan
    -Finds duplicate videos / images based on similarity
    -Windows GUI, Linux GUI and multi-OS Console

    (Please include this in your list!)

  3. Amar said on March 24, 2019 at 5:16 pm

    Hi Kristian,

    I could not find a exe file at the github link. Has it been removed?


    1. Martin Brinkmann said on March 25, 2019 at 7:23 am
  4. Andre said on January 15, 2019 at 9:23 pm

    Easy Duplicate Finder is now commercialware.

    Also THANK YOU Kristian!!! Great program.

  5. Kristian Koskimäki said on January 7, 2019 at 4:25 pm

    I have made a program called Vidupe based after SimilarImages. Vidupe uses FFmpeg, so 99% of tested videos work. There is a Windows exe provided.

  6. Felix said on December 31, 2018 at 11:26 pm

    It worked for me, but I had to install the K-Lite Codecs from I already had the Combined Community Codec Pack so you might need that one too.

  7. Dri said on December 27, 2018 at 9:24 pm

    Seems like a good solution! Please, turn it into an intuitive software, that ordinary users can install and start using it

  8. Pierre said on November 25, 2018 at 11:56 am

    Hello there,
    To solve this issue I managed to build my own open source solution based on python, ffmpeg and findimagedupes.
    Please help yourself :

  9. Unknown said on April 14, 2018 at 1:23 pm

    I am Sure this would be a great Program if it only worked
    I ran the Scan and ” EVERY” file come up failed (Unknow Error)
    does it even work on windows 10….I say “NOT”

  10. perov71 said on September 15, 2017 at 3:16 pm

    Duplicate Files Deleter is use to find duplicate video files on Windows and not effective

  11. jacob2017 said on April 29, 2017 at 2:53 am

    Hello Good day, I use a software called Duplicate Files Deleter, it’s very easy to use and after it finds the duplicate files it lets you chose what you want to do with them (copy/delete/move). You can even check network files and you can check multiple paths in the same scan. This helps me alot. I hope you too.

    1. compared said on June 23, 2018 at 2:52 am

      1. Don’t make us laugh. Try to find this “miraculous” tool duplicates _video_ with different size, extension (mp4, wmv, flv), duration. Hint: your ‘wonderful’ program can not find such duplicates.
      2. Read and understand the article header: the author wrote about searching duplicates _video_ and not ordinary files.

  12. kubo said on December 6, 2016 at 1:56 am

    Cache: Analysis of “f:\video\Zoey Monroe PC_A_w.mp4” failed! (Code: [Unknown error])
    [01:49:05] Files analyzed… Comparing started…
    [01:49:05] No processable files found…

  13. k0ngA said on June 16, 2016 at 6:57 pm

    does not work for me:
    no video can be loaded: Code: [Error to open file]

    1. Martin Brinkmann said on June 16, 2016 at 7:05 pm

      Must be permissions issues on your end. I just ran the application on a Windows 10 machine and it worked just fine.

  14. khz said on May 12, 2016 at 5:44 pm

    this version works with windows 7 ultimate x64

    1. ctruth said on August 17, 2017 at 12:31 am

      KHZ This worked! Thank you very much.

  15. rewanya said on January 14, 2016 at 6:46 pm

    I use Duplicate Files Deleter as it is very effective. It is 100% accurate and performs the scan quickly.

  16. Angelo said on December 27, 2015 at 9:41 pm

    For me best tool is Duplicate Files Deleter.It scans the files and compares them based on Byte for Byte Comparison, which ensures 100% accuracy. You can then choose to delete the selected duplicate or original files. The program is multi-threaded and performs scans quickly.

  17. utking said on October 23, 2015 at 1:55 pm

    What do you mean with copy core.dll?

  18. HDZ said on August 1, 2015 at 12:14 am

    To work on 64bit copy core.dll to core-generic.dll and run as administrator.

    1. Anonymous said on April 19, 2016 at 10:42 am

      thanks, worked like a charm

    2. utking said on October 23, 2015 at 1:54 pm

      What do you mean with copy core.dll to core-generic.dll? is it just make a copy and give it a new name, or copy it to another folder? :)

      1. someone said on December 21, 2017 at 8:58 pm

        just duplicate it with the new name. strange trick and it works. but the app was pretty useless in my tries…

    3. Nanae said on October 22, 2015 at 10:55 pm

      That worked, thank you so much!

  19. barnuble said on March 24, 2015 at 11:03 am

    HamMultiPlayer is a software created to scan your directories (and/or drives) to find and display several files in real time. It can be used to find, move, delete or preview any video/audio file.
    This is freeware and can be used to compare two videos simultaneously…

    May be what you’re looking for ;)


  20. bardy said on October 14, 2014 at 7:08 am

    You can use DuplicateFilesDeleter, it is fast way to find and delete all duplicate files :)

  21. Peter said on February 18, 2014 at 11:56 pm

    This looks very useful. I hope it has safe-guards built-in like “Delete to Recycle Bin”.

    For general duplicate file management I use CloneSpy. It’s not perfect but it’s close.

    I’m still looking for something which can match entire folders recursively. I haven’t seen anything in the ghacks archive.

  22. George P. Burdell said on February 18, 2014 at 7:13 pm

    An “Alternative” to Similar Images seemed like a better choice for me. But before downloading Easy Duplicate Finder, I looked at its CNET Download reviews to get another point of view. There were dozens of strongly worded warnings from other users which made me think twice about choosing it. For one thing, it’s apparently not free!

    Also, this PC World review confirmed what the above users were saying:

    “You can try Easy Duplicate Finder for free, but it will let you take care of only 10 groups of duplicate files before requesting an upgrade. You can continue scanning without upgrading, but you will have to resolve the duplicates yourself. Is it worth $40? Only if you really need the special features and fine-grained control it provides. For simple duplicate file detection, especially on a home computer, a free option would do just as well.

    “Note: The “Try it for free” button on the Product Information page will download the software to your system. When installing Easy Duplicate Finder, it will also install the Webminds toolbar and turn Ask into your default browser homepage. You can opt out of these options during the installation.”

    Another user experience viewpoint:

    So, I’m still looking for a free duplicate scanner program as good as the XP utility called DoubleKiller by Big Bang Enterprises. Maintenance and upgrades to this excellent program apparently stopped with Version in 2007.

    1. jayden benjamin said on April 11, 2016 at 6:57 pm

      I would recommend you to try Duplicate Files Deleter program

  23. Dante said on February 18, 2014 at 6:52 pm

    Been looking for something like this for so long that I gave up looking. Thanks.

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