Duplicarius

Duplicarius is a no frills duplicate file finder for your Mac.

• Simple: Open or drag a folder and click 'Find Duplicates'
• Reliable: Takes every single bit of data into account – yes, also in resource forks
• Fast, highly optimized scanning – won't waste CPU cycles superfluous animations

Photo import stumbled over its own feet and now you suspect that your picture folder contains lots of duplicates? Cloud sync messed up and created many versions of the same file with cryptic name appendages?  
Duplicarius will help you sort this out by finding duplicate files inside a selected folder. It reliably compares every bit of file data, in a fast and efficient way, but without taking potentially dangerous shortcuts. It has a simple, clutter free user interface, not wasting space and time with unnecessary distractions – just right to get the job done.

The core functionality is free, additional convenience functionality is available as a single, one-time In-App purchase.