‘Similar Image Finder’ is a simple freeware duplicate image finder


I recently cleared all of my images off of my phone, and ended up with hundreds of duplicate images on my hard drive (due to the fact that I had downloaded/synced most of these images in months past). I needed a simple and straightforward duplicate image finder, and found one in a freeware called ‘Similar Image Finder’ .

‘Similar Image Finder’ is very easy to use, and revolves around a single number: a metric called ‘minimum similarity’ which is roughly the percentage of ‘exactness’ that you wish to use. This number can range between 100% (for an exact unresized, unaltered duplicate) and will let you can experiment with values in the middle to identify images that ‘look like’ each other. However, in our test of this software the ‘minimum similarity’ number loses its usefulness pretty quickly at just under 90%, where the two paired images might as well be paired at random.

Similar Image Finder Screenshot

Sorting results: you can click a column header to sort by it, but somehow cannot add ‘size of file’ as a column. This means that while you can sort by the ‘similarity’ score, you cannot sort by file size, which is what most people who want to remove hard drive hogging duplicate images would be interested in doing. A rather strange omission.

But the program will let you determine which is the original and which is duplicate based on your choice of: file size, creation date, or pixel size.

You can shift-select bunches of files to perform operations on them,

The verdict:

If you are looking for an image  deduplication program that is easy to use(and free), then you will like this program.  There are other image de-duplication freeware that have more options (esp. options for filtering of results),  and might offer better results, but they are also more involved and have a bigger learning curve.

Users who are looking to get rid of exact duplicate files can set the figure at 100% and be done with it, while others who want a more sophisticated de-duplication scan involving altered or visually similar images can place less exacting criteria and experiment with the results.

Using a single quality criteria percentage is, in theory, a very useful and user friendly concept. However, in my experience, the ‘similarity number’ becomes meaningless (and rather useless) just under 90%, where the two paired up images can be very different and still be reported as potential duplicates (see the example in the screenshot below, which came in at 87% similarity). The algorithm seems particularly vulnerable to flag blank (mostly white or mostly black) images as duplicates for all sorts of images erroneously.

Similar Image Finder Screenshot2

Wish list: this program can be easily improved. If the algorithm would be careful around mostly blank images, the results can be much better. Also, if other criteria could be added as columns to filter by, such as size or others. The option to CTRL-selecting individual items would also be a great help to users (as opposed to the current shift-selecting only).

Go here to download Similar Image Finder (Windows).

  • Kev

    Very nice! I found it did a good job when set to 92%, at least for my purposes. I was able to very quickly delete about 100 identical or very similar images across multiple folders, an almost impossible manual task.

    It took me a while to figure out I needed to press the DELETE key to delete the selected photo, pressing ENTER is enough to affirmatively dismiss the confirmation dialog.

  • Bas

    Thanks for the review. I tested this new tool I did not know before. I didn’t find the interface convenient.

    I like VisiPics more, it also looks aged because it is. But is twice as fast. And found more similar images.

    The first run was at 90% similarity, it returned 2 exact duplicates. The second run it tried the default 75%, it returned 41 pair of images. This returned very bad results. Returned images not even maybe duplicates, not even close! None of the 41 pairs looked like each other. I could also make a script which return 41 random image pairs. So it is indeed completely useless under 90%.

    You can also compare images a little better with VisiPics because VisiPics shows the images in the same ‘preview’ area and when you move over the other picture it will show the other picture. So you can make a good comparision.

    You can also save the ‘Project’, so the next time it does not have to open every file again. Tried this, the second time it takes only 12 seconds to process/compare 3777 pictures instead of 2 minutes.

    If you haven’t reviewed VisiPics I would recommend doing! It can be downloaded here:

    It would be nice if the author could create a new version with a slightly updated database. But then again, it works almost flawlessly 🙂

  • 8bitmore

    Thanks for another good tool-find – mainly leaving a comment here to note that the multiple bars/headers on the main page (http://www.freewaregenius.com/) is really pushing the content/posts far too long down on the page.

    • SamerKurdi

      @ 8bitmore: not sure what you mean by the multiple bars/headers (and the link didn’t work). Would you upload a screenshot so I can see? Thanks.

      • 8bitmore

        The link works ok – I just mean to point to the frontpage, there’s nothing functionally wrong with it; here’s screenshot to demonstrate what I’m talking about: http://i.imgur.com/kIjGkBE.jpg

        • SamerKurdi

          Yes I see the point. I will probably just remove the ad, since it is making me no money whatsoever.

  • Alice Harding

    Shame about this. The set up is brilliant – the best of about a dozen I have tried as you get almost a full half screen of each picture being compared but it is not very good at finding duplicates and pairs up files that aren’t even similar, so it’s no good.

  • Jim

    I love big compare picture boxes and zooming to original size on mouse move in these boxes. It makes some mistakes on blank images but it can be ignored. The fastest one among the image comparer softwares I have tried before. So must have on computer.

  • Jezze

    Does no work very well with black & white sketches. Event with most accurate settings many 99% matches are completely different.