Some photos are not syncing between iMac and iPhone

Question

Some photos are not syncing between iMac and iPhone

I currently am trying to sync two albums in photos with my iPhone. What I am finding is that some, but not all, photos do not sync. I cannot find any commonalities between the files and I have tried turning the syncing off and back on again to no avail. I also notice that from sync attempt to another different photos do not sync and sometimes photos that previously were not syncing now suddenly are. I do not use iCloud Photos because the cost would be prohibitive. My iMac is running macOS 15.5 and my iPhone is running iOS 18.6.

Any ideas?

iMac 27″, macOS 15.5

Posted on Aug 3, 2025 10:12 PM

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Answer 1

Aug 3, 2025 11:51 PM in response to Mark Castleman

So you are syncing macOS Photos system library via Finder via USB to iPhone, right? That has historically been more or less flaky no matter what. So often there are missing images, duplicate images or blank images.

Sometimes repeated syncs might make it better but not perfect. I have sometimes got better results by excluding a troublesome album, syncing, including that album again and syncing. Or by starting from almost scratch by deleting all synced photos from iPad or/and by deleting "iPod Photo Cache" and letting Photos re-create it while syncing. Starting from scratch by creating a new Photos library and syncing does not help either. Keeping Photos active in the background or quitting it before syncing or/and restarting the Mac does not help. I guess I have tried all troubleshooting variations.

Yes, my Photos library has been stored on internal MacOS Extended or APFS volume as it should (non-Mac volumes like exFAT, network shares, cloud storage, Time Machine volumes are not supported and might corrupt the library). And Photos has been given a few weeks to finish its housekeeping by adding faces etc. No, I have never used 3rd party virus apps or "cleaners" that often corrupt the system.

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Answer 2

léonie

Level 10

199,927 points

Aug 4, 2025 01:49 AM in response to Matti Haveri

Matti,

as I can no longer test the selective synching of albums, because I am now using iCloud Photos Library, could you please tell me - is there still an iPod/iPad/iPhone photo cache folder inside the Photos Library package? The old knowledge base article describing this cache has gone is now only found at the wayback machine, so I suspect the cache has gone as well.

https://web.archive.org/web/20150104214842/http://support.apple.com/en-us/HT203156

Corrupted files inside the photo cache folder could cause random results when syncing. Does this cache still exist? If not, do you know, which has been the last version of Photos creating such a cache?

léonie

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Answer 3

Aug 7, 2025 11:48 AM in response to léonie

léonie wrote:

is there still an iPod/iPad/iPhone photo cache folder inside the Photos Library package?

"iPod Photo Cache" is still there in Sequoia and it is generated when syncing via Finder and USB to iPhone/iPad.

Inside it there are "Photo Database", "Apple TV Photo Database" and numerous folders containing thumbnails that GraphicConverter can readily open. My Photos library is 408 GB (36 000 images and 2600 videos) and "iPod Photo Cache" folder inside is 66 GB.

p.s. Obligatory warning: manually messing inside Photos library might corrupt it so make a backup before doing so and be careful.

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