Quick answer
Never open the Photos Library package and delete its internal files. Use Photos to remove unwanted items and review Recently Deleted. If you use iCloud Photos, Optimize Mac Storage can keep smaller local versions when space is needed. Another option is moving the entire library to a correctly formatted external drive after creating a backup.
Why this happens
- Original photos, 4K video, Live Photos, RAW images, and edits can be large
- Download Originals to This Mac intentionally keeps full-resolution local copies
- Deleted photos remain in Recently Deleted temporarily
- Multiple Photos libraries can exist in the Pictures folder
- Exports may create additional copies outside the library
A safe step-by-step plan
1. Measure the library without opening it
Quit Photos, find the Photos Library in Pictures, and use Get Info to see its size. Do not choose Show Package Contents for cleanup.
2. Review inside Photos
Use the Duplicates album when available, inspect large videos, and delete only media you recognize. Confirm important originals have a backup.
3. Understand Recently Deleted
Photos retains deleted items for a recovery period. Emptying Recently Deleted makes the removal permanent and may sync through iCloud Photos.
4. Consider Optimize Mac Storage
With iCloud Photos enabled, Photos > Settings > iCloud > Optimize Mac Storage allows macOS to keep space-saving local versions when storage is tight.
5. Move the whole library carefully
Apple supports moving a Photos library to a Mac-formatted external drive. Follow Apple's steps, open the moved library successfully, and keep a separate backup before deleting the original.
What not to do
- Deleting files inside the library package
- Treating iCloud sync as the only backup
- Moving the library to a Time Machine disk or an unsupported network/cloud location
- Disconnecting an external library while Photos is open
How DiskSift can help
DiskSift is a local Mac storage analyzer. It shows the largest categories and files, lets you sort and reveal results, and separates conservative Safe to Delete recommendations from personal files that need your judgment. File names, paths, contents, and scan results stay on your Mac. Start with the free edition and review every action before moving anything to Trash.
Frequently asked questions
Will Optimize Mac Storage delete my originals?
Full-resolution originals remain in iCloud; the Mac can keep smaller versions locally. Verify iCloud sync is complete and understand your iCloud storage plan first.
Can DiskSift clean inside Photos Library?
DiskSift should help identify the library's size, but photo removal belongs inside Photos so the library database remains consistent.