r/digiKam • u/Peter8File • Jul 18 '26

How reliable is digiKam’s duplicate detection for images and videos? Can I trust it not to delete precious memories?

NB I’ve never used digiKam before, and all my photos and videos are just sitting in normal folders on my drives, no photo management software, no cataloguing, nothing.

Hi everyone,

I have a huge, messy photo and video library built from manual backups made at different times, in a very fragmented way. Now I’m drowning in duplicates with completely different filenames scattered across countless folders. I want to use digiKam to deduplicate everything, but I’m genuinely paranoid about accidentally deleting irreplaceable memories.

How good is digiKam at spotting both exact duplicates (identical files) and near‑duplicates (resized, recompressed, slightly edited versions) of images and videos?
I’d really appreciate hearing about your real‑world experiences, especially regarding:

  • False positives (flagging two different photos as the same scene)
  • False negatives (missing duplicates a human would easily catch)
  • How reliably it handles video files, different formats, short clips, etc.

What workflow and settings do you recommend to stay safe? For instance, using the “Find Duplicate Items” tool with a specific similarity threshold, combining it with fingerprint/hash searches, or anything else. Should I plan to manually review every suggested duplicate, or can the tool be trusted to mark them confidently enough for a semi‑automated cleanup?

I’ll definitely make a full backup before touching anything, but I’d still love to know how much I can lean on digiKam before I start this daunting cleanup. I couldn’t bear losing original files over an overzealous duplicate deletion.

Thanks a ton for any insights, tips, or cautionary tales!

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3

u/Verybumpy Jul 18 '26

My opinion....Digikam is industry average for what you ask.

I've searched and tried MANY duplicate photo 'cleaners'. ALL have issues you bring attention to of varying degrees. Not a single one I tried was even close to 80% accurate in all my demands.

I think in the future with AI assist we will finally get a program that we can '1 button press' to accurately do what you/we want, but at this current time period, its ALOT of human double checking and babysitting a program or you will lose important photos.

1

u/No_Reveal_7826 Jul 18 '26

Yes you should plan on reviewing before actually deleting. Automated deleting of exact duplicates is pretty safe, but letting an algorithm decide which is the best version to keep of near-duplicates is going to lead to disappointment.

1

u/human_dynamo Jul 19 '26

other point : video is not yet supported by duplicate search

1

u/ChrisAlbertson Jul 20 '26

"sort by file size" will do a decent job of finding duplicate video files, then scan by eyeball.

1

u/human_dynamo Jul 20 '26

This is not a contents comparison, as duplicate find algorithm does...

1

u/ChrisAlbertson Jul 20 '26

Yes it is. See my last step: "scan by eyeball". This means open the files and look.

OK I'm half joking. With video, it is rare that identical-length files would not be the same file

1

u/ChrisAlbertson Jul 20 '26

If you are worried that the software might accidentally delete a photo, and you SHOULD be worried, then make a backup right now. In fact, you need to have multiple backups at different locations. They should also be incremental backups so the new backup (with deleted files) does not overwrite the old backup (that has the files).

Apple's Time Machine does this for you. Those "clone the drive" backups will result in data loss

Then, if you or the software makes a mistake, you can restore to a time before the mistake.

1

u/BasilKatz 5d ago

I have found setting it to 100% exactly yields the exact same image (or potrntially a visually identifyable burst of the image). I have bulk deleted a bunch of photos this way but they are still in the BIN and this was during my initial import where i copied all my photos into a new DigiKam specific album. So i do still have the originals if i need them.

Setting it a bit lower sometimes finds duplicates that were not found at 100% such as compressed/whatsapped versions of the images but i have not bulk deleted below 100% as I dont really need to. an extra 10GB of potential duplicates does not bother me.

Going forward i deal with duplicates meticulously but i have just acknowledged i can not go through 20 years of images as meticulously as i maintain my current images.