Tago's Similar Image Finder searches your PC for similar images; not just duplicates but also near-duplicates that similar tools miss. It displays close matches side-by-side in preview windows so you can verify, keep, or delete files. It's handy for finding a series of snapshots or almost-identical images saved under different names. Similar Image Finder is freeware for Windows XP to 8.
As we noted, Similar Image Finder uses a pair of auto-zooming preview panes to display differences between images. A file list, controls, and various settings are in the lower portion of the layout. Settings include searching subfolders, interface language, image file types, and a slider for configuring searches between More Accurate (Slower) and Less Accurate (Faster). We clicked "Folders to Search" and browsed to a wallpaper archive that needed some attention. Similar Image Finder works fast. It flagged four potential duplicates and displayed the first pair. We could swap the images, delete duplicates, move files, ignore similarities, and more. Clicking column headings rotates results, which is handy when Similar Image Finder finds a lot.
Similar Image Finder helped us clean up some image archives in no time with minimal effort. That counts as a success in any book. Nearly every duplicate file finder we've seen has a small preview window or two that can identify files but not show their differences. Similar Image Finder's large preview windows make a huge difference. Whether you're a pro photographer or just someone with a lot of saved images, Similar Image Finder can help you keep it clean.