Size of Photos Library makes no sense st all

I have a question regarding the size of my Photos Library. I have 57 GB of photos and Videos uploaded into my iCloud Photos. Somehow on my new Mac Mini the Photo Library file takes up roughly 80 GB although I have enabled the space saving selective sync feature (I don‘t know the official english term for this) and according to the information in my system preferences, these photos take up another 8 GB of storage on my Mac. (Happy to upload a screenshot of this later today, if my description does not make sense). Does anybody here have an idea about this?

Many thanks in advance.


As far as I can see on my side, a photo librarytakes more space than the total of photos in the library. I also noticed tat it can take several hundred of megabytes after I detel the photos and emptied the trash. I found the following reasons :slight_smile:

  • Photos creates thumbnails of your photos, which are taking spaces by thenselves.
  • Photos saves metadata of faces, locations in a database withing the library, which also takes some space

These are the reasons for the 23 GB extra space on top of your 57.

Something I can’t guess are the 8 GB on top of the 80…

Is there a reason for you to have your full size photo in iCloud rather than on your Mac Mini ? I’m curious (because I’m having all my originals on my iMac, not cloud)

Hope this helps a bit.

Thanks for your reply. I keep them in iCloud to have them synced across my Apple devices (and as a means of backup). I was thinking about keeping all originals in my Mac Photos Library and doing an additional backup from there. Now it seems like that for some reason my roughly 60 GB of Photos would take triple or so that amount of storage space on my Mac. So I would like to fix that problem first.

Here are the screenshots, which I hope clarify my problem a bit (despite being in German):

Size of my Photos Library in iCloud (according to my iPad):

Size of my Photos Library on my Mac:


The next screenshots show the issue, that on top of the size of my Photos Library, there are another 7,67 GB of photos on top of my Photos Library, which I assume are the local thumbnails of my photos and the few photos that are downloaded in full size (as I have enabled the option to optimize the local storage and not load all originals to my Mac):

The last screenshot shows my iCloud Photos settings, where you can see, that I have enabled the option to optimize Mac storage space (as opposed to the option where all originals are downloaded to the Mac):

Does anyone here have an idea what I could try?