Dupe guide

Migrated from an old Mac and ended up with duplicates

Migration Assistant can leave you with two of everything if your new Mac already had files. Here's how to clean up.

4 min read

Migration Assistant is mostly great, but it has one common failure mode: if your new Mac was set up with iCloud sync (Desktop & Documents, Photos, etc.) before you migrated from the old Mac, you can end up with the same files in two places. Sometimes Migration Assistant creates a Users/your_name (old) account. Sometimes files land in Migrated Items on the Desktop. Either way, two of everything.

Survey what happened

  1. Open Finder and check /Users/ (Shift+Cmd+G > /Users).
  2. Look for any account names other than your main one — your_name (old), your_name 1, or similar.
  3. Check your Desktop for a Migrated Items folder.
  4. Inside Pictures, look for a second Photos Library.photoslibrary or .migratedphotolibrary bundle.
  5. Note the sizes of these folders — they’re typically the source of the duplication.

Dedupe between the migrated content and your new account

  1. Download Dupe and open it.
  2. Click “Add Folder” and add both your main home folder (Documents, Pictures, Desktop, Downloads) and the migrated folder or secondary user account.
  3. If migrated content is in a separate user account, you may need to grant Dupe Full Disk Access in System Settings > Privacy & Security so it can read those folders.
  4. Click “Scan.” Dupe hashes every file across both locations.
  5. Review duplicate groups. Each shows the path so you can tell whether a copy is in your active home folder or in the migrated holding area.
  6. Generally, keep files in your active home folder and trash duplicates in the migrated area.

Special case: Photos libraries

If both your old Mac and new Mac had Photos libraries that got merged at migration, you may now have two .photoslibrary bundles in Pictures. Don’t just delete one — open both in Photos.app first to confirm which one your library is currently pointing at (Photos > Settings > General > Library Location). The other one can be safely scanned with Dupe and trashed after you’ve verified the active library has everything you care about.

After cleanup

Once duplicates are gone, you can usually delete the migrated user account or empty the Migrated Items folder. In System Settings > Users & Groups, removing an unused migrated account also reclaims space.

Safety

For migrations where iCloud sync had already populated the new Mac, this kind of cleanup typically frees 100–300 GB.

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