The only thing this program did better than Awesome, which I've been using for a while now, is find a 90-degree rotated image and its duplicate non-rotated version.
Other than that, it's much slower (maybe finding the rotated copies has something to do with it, I don't know). It calls images duplicates that are in no way similar. It doesn't indicate how similar the images are nor allow you to limit the "closeness" factor so you don't have to go scanning through a bunch of obviously dissimilar images.
For a first-time user, it was not obvious what to do next, once I selected the folder to scan. There was no button that said "Compare" or some other verb suggesting an action to take. Only "Timeline" and "Similar" which I took to be properties, not actions!

Will be uninstalled.

I downloaded awesome_photo_finder.exe and scanned it with AVG Internet Security.

Result: Found MalSign.OpenCandy.3CF (ranked 2/3, i.e. not worst, not best, but medium)

OpenCandy is a software that installs an additional program to display and/or download to your device unwanted advertisements, toolbars and may be considered privacy-invasive.

Following Stew's suggestion, I started the install and AVG popped up and offered to clean the file, which it did. I haven't had time to test it yet, but it's somewhat reassuring to think that AVG assures me that it protected me. I'll find out if it really did.

It's quite meaningless just to say I use 'X' without even comparing it to the GOTD offer.

Download, installation and activation went smoothly. Searching is really way too slow. But what's important, the app does not do what I expected. I don't need it to find duplicates/similars - that I can do myself. What is the real pain is to select the ones to delete. I expected the tool to help with this but it did not. Plus, some 'similars' found were completely different pics.

Uninstalled 10 mins later.

Downloaded, installed, ran program
Scanned picture file folder (over 7000 files), but only found dups taken with iPhone, not camera
Uninstalled

works with jpeg
does'nt work with gif or Canon's raw files (.cr2) or small files (120kB)
quick, but freezes if too many files (cancel is however allways available)

I thought I would try this free offering after reading all the comments and I'm glad I did,I did not realize I had so many duplicates photo's in my Pics folder, 23000 pics and it found 430 in 22 mins a keeper for me, I also tried some of the suggested one's mentioned in the comments and they were not as good as this one
thank you GAOTD and Greenline-Soft Labs

Installed and tested on Windows and 10 and DupHunter didn't find any duplicates when I pointed it to my documents folder. Ok, maybe there aren't any (I didn't really believe that), then I went in and copied one of my files and pasted it back to the same folder. Now there are two files that are the same but with different names. Rerunning DupHunter, it came back and once again reported no duplicates. Uninstalled DupHunter as it's a great idea and would have been useful but it doesn't work.

>> ALL, esp. Gary Doyle

The site for http://www.duplicate-finder.com/files/awesome_photo_finder.exe is a flagged site for hidden unwanted software. Be advised, it MAY be my anti-UCE programs having a go, but proceed with caution.

Gary, if this is not correct, please post.

At this point in time, processing RAW is a must. This prog cannot do that, so not much use. Also, I ran it on a bunch of JPG - results are all over with more misses than hits. The time function is useful, but limited, because it does not look for EXIF for the final comparison (neither does the other function). I guess this prog could be useful for a casual cellphone shooter, but definitely not for a serious photographer.

DUFF hunter more like.
Select 'similar' after waking yourself up (Someone mention QUICK?) and it selected a photo of the same property, one taken in daylight and the other at night 5 yrs later from a different angle (Quite clever really - but useless) and 'timeline' suggests photos taken on the same day but of different people, might be considered for deletion.
I can do the same thing from explorer by clicking on 'Date' at top of the folder list.
Nah! Not for me. Removed hastily.
Thanks GAOTD.

I have tried scanning a folder with 5,053 images in it and once it gets to 50% it stops moving and never finishes. It isn't froze or anything because I can cancel the scan.

I have always use Duplicate image finder by runningman
Free version will only search one folder location or drive

Installed and registered with ease and opens up a dreary looking mud coloured interface.

For my first test a JPG image was saved with different compression levels it was also resized, all were placed into a single folder.
The program rapidly found that they all had the image same and marked them as duplicates.

In my second test scanned a small partition that I know has many, many duplicate files and it found them.
It displays them as thumbnails in a window but to get information you need to select them individually, this makes removing them a tedious business.

From my own programming experience I know it is difficult to find a useful method of organising the results.
Certainly in my second test it would have been better if I could have grouped them by the folder names or paths.
Using Timeline many of the selection disappeared, a bit of a surprise.

In my first test the files were put in the root directory of a partition and when that folder was scanned it quickly found the duplicates.
When the same test was done using the folders and subfolders menu selection it did not find the duplicates, a serious bug.

When it does a scan using the Similar selection the level of similarity was not possible to set.

From a user point of view it is not particularly pleasant to use and the fact that it got different results when the selection was a Folder or Folders And Subfolders when it should have been the same result an obvious bug.

It still needs a lot of development and I will not be keeping it.

Have installed and successfully activated according to GOTD website, and program works well until I try to delete duplicates, when it asked me to enter the resistration key. Where do I get this from? Please help!

I have been using Awesome Duplicate Photo Finder < http://www.duplicate-finder.com/photo.html > for some time and can't believe how accurate, how fast and how good it is.