I recently switched to Mac and spent way too many hours on PC trying every duplicate removal app, eventually discovering that byte-by-byte checking was necessary to get accurate (safe) results, and finally then settling on AllDup as the best app for this purpose.

Mac options seem more limited and I have not found any that do byte-by-byte checking, they don't even necessarily state on their website what algorithm(s) they use! Any tips? Must also work on Yosemite.

  • SHA-1 guarantees uniqueness of file data with an extremely high probability. Comparing files byte by byte would be very inefficient and pointless.
    – glebd
    Commented Mar 26, 2015 at 21:38
  • 4
    I would be very surprised if you find files with the same SHA-1 or MD5 hash but different content on your computer. See apple.stackexchange.com/questions/118566/… for some options to find dupes based on hashes.
    – nohillside
    Commented Mar 26, 2015 at 21:43
  • You might want to ask this on Software Recommendations Stack Exchange. Be sure to specify as many requirements as possible.
    – user83961
    Commented Mar 26, 2015 at 21:51

3 Answers 3


You could do worse than to try dupeGuru, available from Hardcoded Software, I've had very good results with it. It presents numerous options for fine-tuning your search and will perform byte-checking comparisons.

In addition to the standard dupeGuru there is a music edition as well as a picture edition for more specific media searches. It's free so give it a go with some test files and see what mileage you get.


Try to instal this one https://www.cleverfiles.com/duplicate-file-finder-remover.html It's a good freeware alternative to some paid programs. This app scans your Mac for all kinds of duplicates and does this really fast. It also features flexible auto-selection rules, so you won't need to scoop through the duplicates manually.

  • The page you linked to doesn't specify whether the app actually performs byte-by-byte comparison. Commented May 11, 2017 at 10:59

I think the duplicate finder Gemini 2 is such an app you are finding, it can find duplicate files by contents(byte-by-byte checking) and file name, it even can sort out the similar photos in your photo library. Works quite well for me so far, you are going to give it a try.

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