Photos for OS X is great for pictures and videos on the Mac, but how does it work with multiple Macs?
I've had a multi-Mac household pretty much since college, rocking a laptop and desktop in addition to miscellaneous iOS devices throughout the years. Dropbox and iCloud sync made most of the pains of using several Macs disappear, but iPhoto was always a problem. My laptop is tiny! My iPhoto library, not so much.
Thankfully, Photos for OS X — paired with iCloud Photo Library's Optimize Storage feature — makes working with and syncing multiple Macs a breeze. Here's how you can do it.
How to use Photos for OS X and iCloud Photo Library with multiple Macs
Here's a quick, simple breakdown on setting up your Macs to support Photos and iCloud Photo Library.

I recommend starting with your biggest iPhoto library; it'll usually be on your desktop Mac. When you open Photos for the first time, your library should import automatically; if it prompts you to create a new library, your Photos library may be stored in another location on your Mac, and you may need to manually open it.
Once you've imported your biggest library on your Mac, make sure iCloud Photo Library is turned on and syncing by going to Photos > Preferences > iCloud and checking the iCloud Photo Library checkbox. I highly recommend choosing the Download Originals to this Mac option if your primary computer has the space, so that you have one master copy of your images stored locally, rather than relying on everything in the cloud. (See Rene's How to back up your iCloud Photo Library article for more information.)

Now, open your other Mac, and launch Photos. If you have an iPhoto library on that secondary Mac, follow the same steps as above — import your library, then turn on iCloud Photo Library. If you have duplicates of the same photo on each computer, iCloud should automatically resolve those conflicts when it syncs, providing you with just one version of your photos when the sync process finishes.
If you don't have an iPhoto library on your secondary Mac, create a new library in Photos and turn on iCloud Photo Library. If you want to save storage space on this secondary Mac, make sure Optimize Mac Storage is selected: This will save a certain percentage of images and video locally to your device, while providing thumbnails of all the others for you to download at your leisure.

After you've set up all your Macs with Photos for OS X and the sync process has finished, you're now good to go. From here on out, any time you add photos, they'll sync to every computer you've set up with Photos for OS X.
What syncs, what doesn't sync
Photos for OS X syncs a lot more than just your original photos and videos. According to a support document on Apple.com, here's what else you should expect to see sync:
- All folders and albums (Mac and iOS)
- Smart Albums (Mac only)
- Keywords (Mac only)
- Searchable keywords based on Faces tiles (Mac only)
- Key photo selections (Mac only)

There are a few things iCloud Photo Library won't sync, however. Here's Apple's list:
- Books, cards, calendars, and slideshows
- Keyword shortcuts
- Unused keywords
- Last imported album on the Mac in question
- Your Faces smart album and any tagging you've done
For those not using iCloud Photo Library
If you've chosen not to enable iCloud Photo Library, Apple still offers you free syncing of your last 1000 photos via My Photo Stream, which doesn't count toward your iCloud disk space. This will sync and download images you've imported or taken on other devices, but you won't have the option to optimize your storage or sync your albums.
Reader comments
How to use Photos for OS X with multiple Macs
This seems to assume both macs are signed into the same iCloud account. But unless I've missed something, I don't think this will work for my wife's iMac and iPhone (signed into her iCloud account), and my MacBook and iPhone (signed into my iCloud account).
Yeah, being married and wanting to share photos but not share an iCloud account doesn't appear to be an option within Apple's ecosystem. So, it looks like we will have to look at other options for the time being.
Simply separating the iCloud ID that iPhoto uses, similar to how iTunes allows a separate Apple ID from the iCloud ID would solve this problem.
However, I see Apple either not solving this problem or trying to force family sharing onto iCloud accounts.
Yep, I'm writing a follow-up on this soon.
Awesome, thanks. The only solution I've found is to host the entire library on a shared drive (in my case, external HD) and disable iCloud Photo Library. Photos will only allow one person to access the library at a time, which is good to prevent any corruption of the database. Any photos will have to be manually added to the library by my wife and I.
Here you go!
Thanks - it doesn't really answer how to handle one shared library and two separate accounts and macs, but I guess there isn't an actual solution.
Right. it would work but it would take a lot of manual interaction to upload the photos to the shared album whenever you import, and you would have to empty it out once you got to 5000 photos.. I really wish Apple had decoupled the iCloud Apple ID from the OS and allowed you to set one for the Photos app.
My wife and I will be forced to look at other amazon, flickr, google and others to see what will work the best.
Agree. Works, but not clean. Also, as it relates to using Family Sharing to get photos/videos from one ID to another, in my experience the videos did not transfer over from the Family shared album upon import. Also, the photos are not full resolution as shot, e.g., 8MP on 6 Plus.
I do the bulk of the picture taking and all of the management. For now, my best solution is to AirDrop my wife's files to one of my iOS devices, which automatically imports full res photos and videos.
How would this work if you keep your photos on an external drive? TIA
I'm doing that right now. I had to navigate to the library at time of Photos setup, and that location was adopted by Photos for its own. So nothing much changes.
5gb free for a photo library is too small.
It's also a safe guess that with Family Sharing, the paid iCloud data doesn't share. I'd be happy to pay for the 2nd tier (400gb?) for both myself and my wife, but the 20gb plan is slightly too small for both of us, meaning we would both need the larger plan, when really we could share that much for a while. I also don't think iTunes match shares either on family sharing plans. Those 2 issues make me not want to jump into this pool.
Love this makes it like iphone and ipad! Thanks APPLE!
Thanks. Great article. Any thoughts on using iTunes (Match) on two Macs? I tried it and it didn't work causing all sorts of issues with play counts and ratings.
I'm uploading my 100GB master library from my main machine right now. Looks like this may take a month to do from NL in EU. And I do have a fast connection here in the middle of my city.
I hope iCloud Drive will speed up significantly when Apple brings the two planned EU data centres on-line in a few years. In the mean time we're camping out in the cold.......
It's super-slow all around, mostly due to the fact that everyone and their mother is uploading to iCloud right now. Give it a few days. :)
Indeed, it took four days. Better than the month I anticipated ;-)
Note that when Serenity says it syncs 'all folders and albums' on iOS and Mac that includes the Recently Deleted folder in Albums tab. I had 1000+ photos/videos in that folder on iPhone that were included in the initial Photos sync on a second Mac. This had the unfortunate result of adding all of those 1000+ Files back into Photos everywhere else, requiring me to go back and re-delete those files.
I recommend doing a Delete All from the Recently Deleted folder on all iOS devices (they should sync), as well as the File>Show Recently Deleted files on the primary Mac (which does NOT sync with iOS), then proceed with setting up multiple Macs.
Hey guys, any suggestions of how to manage the Photos Library if you're sharing one iMac with two logins. My wife and I use one desktop but want to share the same library. When I try to link her Photos library to the one in my account I get a permissions error. Any suggestions so we can both use it? Or should mine be the master and hers only an optimized version?
I'd like to know this too - how can two logins on one iMac share a SINGLE Photos library? This used to work just fine with our iPhoto library in /Users/Shared, but I too get a permissions error once the library is converted to Photos. Manually trying to set the permissions of the library in Finder doesn't help. I don't want to store the library in the cloud (hundreds of GB), I want the library on a local hard drive.
I love imore! This is just what I was trying to figure out before starting the transition to Photos. Thanks!
Thank you for this article. Just upgraded several computers to Yosemite and encountering the new software Photos. So does Photo Stream disappear in the desktop version of Photos? Or is it only once you enable and pay for the iCloud Storage? If yes, under what name - album? - do the latest images appear on the desktop Photos? Thank you!
I am having a problem getting my photos downloaded on my new iMac. I have set the preferences to "Download Originals to this Mac". The message at the bottom of the Photos tab says "56,625 Photos, 817 Videos, Downloading 59,353 items". But it's just stuck at that point without further downloads. Quitting and re-opening the Photos App doesn't help. The only time that a photo gets downloaded is when I enlarge a photo using the Space bar, and then the download count reduces by one. Please help !
I wonder if I can game this system and sync my many macs by paying for enough storage for one month and then enabling the photo stream option? It seems like this would sync all of the older photos in your library and if the Mac is set to download the high quality versions, you could then allow photo stream to keep you current?