Three copies of every sunset: finding and merging duplicate photos on Mac
Burst shots, AirDrop round-trips, imports from multiple devices — duplicates pile up fast. The good news: macOS has a built-in way to find them. The better news: it's careful enough that you won't accidentally nuke the only copy of a photo that matters.
The Duplicates album in Photos
Open the Photos app and look in the sidebar under Utilities. There's an album called Duplicates. macOS scans your library in the background and groups photos (and videos) that are exact or near-exact matches.
Each group shows the duplicates side by side. You can tap Merge to keep the highest-quality version and move the rest to Recently Deleted.
How "Merge" works (and why it's safer than Delete)
When you merge duplicates, Photos keeps the version with the best resolution, the most metadata, and any edits you've made. The other copies go to Recently Deleted, where they stay for 30 days before permanent removal.
This means you have a full month to change your mind. No photo disappears instantly.
Step-by-step: cleaning duplicates safely
- Back up first. Before any bulk operation on photos, make sure you have a recent Time Machine backup or a copy on an external drive. iCloud is not a backup — it syncs deletions.
- Open Photos → Duplicates. Let the scan finish. On a large library, it may take hours the first time.
- Review before merging. Click each group. Most will be obvious — same photo, same moment. But occasionally Photos groups shots that are merely similar (same scene, slightly different framing). Those are not duplicates — skip them.
- Merge in small batches. You can select multiple groups and merge at once, but start with a handful to get comfortable with the results.
- Check Recently Deleted. After merging, go to Recently Deleted and verify that nothing important ended up there. If something did, recover it immediately.
What about duplicates outside the Photos Library?
The Duplicates album only finds copies within the Photos app. If you have loose image files scattered across Desktop, Downloads, or other folders, Photos won't detect them.
For those, you can use Finder's search: filter by Kind → Image, then sort by name or size to spot obvious duplicates. It's manual but safe — and you're always in control of what gets deleted.
How duplicates get there in the first place
- Importing the same SD card twice. Photos warns you, but it's easy to click through.
- AirDrop from someone who already shared those photos. Each receive creates a new copy.
- iCloud shared albums. Saving a photo from a shared album to your library creates a duplicate if it's already there.
- Multiple Apple devices. If Photo Stream and iCloud Photos overlap, duplicates appear during migration.
Once your Photos library is lean, the other half of the storage problem is usually caches and system data. Our System Data guide walks through what else is eating your disk.
Your photos deserve attention. Your caches don't.
Gigatidy handles the boring part — caches, logs, app leftovers — so you can spend your time curating photos, not hunting junk files.
Meet Gigatidy →FAQ
Does the Duplicates album catch every duplicate?
It catches exact and near-exact matches inside the Photos library. It won't find copies stored outside Photos (in Downloads, Desktop, etc.) or photos that are visually similar but technically different files.
Is it safe to use "Merge All" for duplicates?
Generally yes — Photos keeps the best version and sends the rest to Recently Deleted for 30 days. But if your library has near-similar shots grouped together, you might lose a version you wanted to keep. Review a few groups first.
Will merging duplicates free iCloud space too?
Yes. If you use iCloud Photos, the duplicate copies are removed from iCloud as well, freeing storage across all your synced devices.