I have collected all of my photographs onto one hard drive. I'm looking for software that runs on Mountain Lion to assist in finding similar photos so I can review and eliminate redundant files.

My picture store is currently 2 TB, so batch and/or efficient software would be ideal. I know for certain that there are a lot of duplicates, and there are lots of programs out there which can find exact duplicates.

What I am looking for is something which will find:

  1. pictures which are identical except for rotation
  2. pictures which are identical except for size (i.e. an original vs a thumbnail from iPhoto, or an original vs a downsized version for the web, etc)
  3. pictures which are similar

I assume #1 is possible, but I am not sure about #2 or #3. What software can do any or all of these tasks?

  • #3 probably isn't possible, though 1 and 2 should be. – Linuxios Dec 30 '12 at 18:31
  • 1
    #3 is a hard question. I know this, because I worked on a team that was responsible for keeping p0rn (and other bad stuff) off a social networking site. We could blacklist a particular photo, but then someone could change one pixel and upload again. However, think of this as a generalization of the advances in facial recognition software. – Andrew Lazarus Jan 3 '13 at 20:15

The best that I could find and have used is Duplicate Annihilator, which works with iPhoto, and is upgraded for 10.8. You can download and do a run and hopefully get rid and clean your folders the first time through. For what you need you might need a few passes to get the obvious dups, then find the harder to get ones.


I am not exactly sure it will find your #2 and #3 right out of the gate, but since photos are marked with unique timestamps and other meta data, it should find them even if rotated. The similar part is a bit harder as the criteria for similar could be many things. Run through a few times first checking my filename, then maybe dimensions, creation date, etc.


  • Detects duplicates
  • Detects imported thumbnails
  • Detects missing images
  • Easily find and annihilate duplicates created internally by iPhoto or during import.
  • Compare images using different algorithms to detect and understand differences.
  • Detect duplicates using effective algorithms using electronic checksums like MD5.
  • Detect duplicates by using file specific meta data such as filename, dimensions, filesize, Exif creation date or date of creation.
  • Delete duplicates upon detection or mark them with a keyword to make them easily found using iPhoto features like search or smart folders. Only uses standard Apple features and API's. No hacking nor tampering with iPhoto system files. Free updates! Available in English, German, French, Italian and Swedish.
  • This is a good suggestion, however my pictures are not all in iPhoto, in fact most of them are not in iPhoto. – TJ Luoma Jan 1 '13 at 22:30
  • That may be so, but you didn't ask for a solution outside of iPhoto. Organizing them in iPhoto itself is a better solution than not using any particular software. Importing them in all in one place, in itself, might remove some duplicates during import. – donlaur Jan 2 '13 at 18:34
  • I just installed fdupes using the instructions here, macappstore.org/fdupes/#comment-83390 and this command line in terminal identifies exact duplicates, ie files that may have a different name but be exactly identical (checking md5sum). The use of hte command is simple, such as : fdupes -r -A path to the directory to screen > ~/Desktop/Duplicated-files-.txt" – Yves Feb 23 '20 at 15:52

It's not exactly what you're looking for but it will help you easily find those duplicates : http://macpaw.com/gemini

  • But doesn't this only work for files which are identical on binary level? – nohillside Dec 30 '12 at 19:10
  • It can be but I'm not sure... I just found this and it looks really easy to use but the suggestion 'donlaur' gave is maybe more accurate for 'TJ Luoma' his problem than my solution. – tdhulster Dec 30 '12 at 23:59

I've used PhotoSweeper Lite and it did the job for me:



For identical files (bit-for-bit) I use jdupes, works great and is free. Install with brew (brew install jdupes)

PhotoSweeper will do at least #2 and #3. You can get a demo with limited deletion and unlimited identification. Price is more than reasonable given the time you will save. Dunno about 2Tb, but 30Gb was OK and ran in less than 15 secs.

Just paid the developper, usd 12.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .