dupeGuru - dupeGuru is a tool for finding duplicate files on your computer.
fdupes - FDUPES is a program for identifying or deleting duplicate files residing within specified...
Duplicate Cleaner - Duplicate Cleaner: the fastest and most popular tool for finding duplicate files. Over 1 million downloads: Get your copy now! Free and Pro versions available.
Rdfind - Rdfind is a program that finds duplicate files.
AllDup - AllDup is a freeware tool for searching and removing file duplicates on your Windows computer.
Czkawka - Multi functional app to find duplicates, empty folders, similar images etc.