Dup Detector is a very clever freeware utility designed to locate duplicate photos on your hard disk. Dupes are an inevitable part of life if you do a lot of – disorganised – photography, so this tool is probably the single most useful thing you can install if you have images scattered across disks and machines.
It will find near matches too, so even if you have cropped or resized and stuff, you’ll be able to track down the similar images and make a decision on which version to keep. The UI is a little old fashioned and it runs really slowly, so don’t expect to whip through your 7000 images chop chop, but it’s still a very worthwhile download, if only to return order to chaos.
Dup Detector finds duplicate and near duplicate images by opening and reading image pixel data. The program is easy to use, just specify the path and start the scan. You can specify a match % that is required to consider the image a duplicate and preview all found dups side by side with an option to delete either one.