Prevention is better than cure.:
Umbrella reports the duplicates the moment they are created. Forget the boring job of dealing with huge results when using a standard duplicate tool. Umbrella is the only duplicate-prevention tool available on the market. It is unobtrusive, easy to use, and powerful. Umbrella is a perfect Tidy Up 5 complement, and used together they will keep your Mac clean and efficient.

Features:
    •    Search in iTunes database.
    •    Search Photos image files.
    •    Search by files.
    •    Customize criteria to determine the duplicates.
    •    Automatic mark for a fast removal.
    •    Multiple files preview.
    •    Full integration with Tidy Up 5
    •    And many more.

Compatibility: macOS 10.14 or later 64-bit
Homepage: https://www.hyperbolicsoftware.com