Does Apple Photos find duplicates?
Yes, with limits. Since macOS 13, Photos has a Duplicates album that finds exact copies inside your Photos library and merges them. It does not look outside the library, and it does not catch photos that are merely similar. Here is what that means in practice.
What the Duplicates album catches
The Duplicates album is automatic. Photos scans your library in the background and lists exact duplicates it finds, grouped together, with a Merge button. When you merge, Photos keeps one copy and combines the metadata from both, so you do not lose a caption, a location, or a favourite mark that was only on one of them.
It works for photos and for videos, as long as they are true duplicates: the same image imported twice, for example from a phone and from a camera card, or from a restored backup.
Because it runs inside Photos, nothing is deleted straight away. Merged extras go to Recently Deleted, where they stay for 30 days before Photos removes them for good. That is a reasonable safety net for a built-in feature.
What it misses
Anything outside the Photos library
Photos only sees what is in its own library. Folders in Finder, an external drive of old photos, a backup folder from a previous Mac, exported copies on the Desktop: none of these are checked. If your duplicates are the same shot living once in Photos and once in a folder, Photos cannot tell you.
Similar photos
The Duplicates album has no "similar" detection and no threshold to adjust. A photo and its resized export, a HEIC and the JPEG converted from it, a burst of ten nearly identical frames, an edited copy next to the original: all of these look different to Photos, so they stay. For many libraries, these near-duplicates take up far more space than the exact ones.
Re-compressed copies and large libraries
Users describe the detection as weak. A specific complaint is that copies that came back from a shared album, which are re-compressed on the way, are not matched with the originals. Another is that the scan stalls or never finishes on very large libraries, since it runs as a low-priority background job.
When it is enough
- All your photos live in the Photos library and nowhere else.
- Your duplicates come from importing the same files twice.
- You are happy to leave near-identical shots alone.
- You can leave the Mac plugged in and awake long enough for the background scan to finish.
In that case, it is free, built in, and safe. Use it before you buy anything.
When it isn't
- You have photos spread across folders, external drives, or old backups. See the external drive guide.
- You want to clear bursts, resized exports, or edited copies and keep the best one.
- You use Lightroom or Capture One alongside Photos.
- The Duplicates album has been "scanning" for days on a large library.
For those cases you need a third-party tool. The comparison of Mac duplicate finders covers the options, including the free built-in feature as a baseline.
How to use the Duplicates album
- Make sure you are on macOS 13 or later and open Photos.
- In the sidebar, scroll to Utilities and click Duplicates. If the album is missing, Photos has not finished its background scan yet. Leave the Mac awake and plugged in and check back later.
- Each row shows a group of duplicates. Click Merge for a group, or select several groups and merge them together.
- Photos keeps the highest-quality version, combines the metadata, and moves the rest to Recently Deleted.
- If you merged something by mistake, open Recently Deleted within 30 days and recover it.
A few practical notes. The scan only runs when the Mac is idle and on power, so a laptop that sleeps in a bag will not make progress. iCloud Photos libraries are scanned too, but the merge applies across your devices, so check on one device before merging in bulk. And back up first, as with any cleanup.
A common question
People regularly ask whether Apple's duplicate finder compares to the paid apps. The honest answer is that it does one narrow job well: exact duplicates inside the library. The paid and open-source tools exist for everything around that job, which is where most of the clutter on a real Mac lives.
What SameScan adds
SameScan is a Mac app in development that looks where Photos cannot: folders, external drives, and the Photos library together, for both exact and similar duplicates. It shows each group side by side with a suggested keeper and the reason, moves extras to the Trash only, and keeps a restorable log. Nothing leaves your Mac. It is not available yet; join the launch list to hear when it ships.