Photos Library on Mac: why it is so big and what to do
Do not delete Photos Library.photoslibrary. It contains all the photos and videos in the Photos app, plus your edits, albums and people. To free space, turn on Optimize Mac Storage or move the library to an external drive.
Where it is
~/Pictures/Photos Library.photoslibraryWhat it is
The Photos library looks like a single file in ~/Pictures, but it is a package: a folder that Finder presents as one item. Inside are your original photos and videos, edited versions, thumbnails and the database that ties them together.
It grows with every photo you take or import. If you use iCloud Photos, the pictures from your iPhone arrive here too, and by default the Mac downloads the full-size originals.
Do not open the package and move or delete files inside it. The database expects them to be where it left them, and the library can be damaged.
How big it gets
Usually the largest single item in a home folder: tens of GB is common, and hundreds of GB is not unusual for a long-time iPhone user.
How to shrink it the right way
- If you use iCloud Photos, open Photos, choose Settings, then iCloud, and select Optimize Mac Storage. Full-size originals stay in iCloud and the Mac keeps smaller versions when space is short.
- Delete what you do not want inside Photos, then open the Recently Deleted album and empty it. Until you do, deleted items still take space for up to 30 days.
- To move the whole library, quit Photos and drag Photos Library.photoslibrary to an external drive formatted as APFS or Mac OS Extended. Wait for the copy to finish.
- Hold the Option key while opening Photos and choose the library on the external drive. If you use iCloud Photos, open Photos Settings, General, and click Use as System Photo Library.
- Only after you have checked that the moved library opens and is complete, delete the original from ~/Pictures.
What happens afterwards
With Optimize Mac Storage on, opening an old photo at full size needs an internet connection while the original downloads. With the library on an external drive, Photos only works while that drive is connected.
How Diskzy handles it
Diskzy shows how large the library is on the disk map. Managing what is inside it is a job for the Photos app.
Related guides
- Messages attachments~/Library/Messages/Attachments
- iPhone and iPad backups~/Library/Application Support/MobileSync/Backup
- iMovie render files~/Movies/iMovie Library.imovielibrary
- Trash~/.Trash
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