iMac iCloud Photos not syncing; need setup help

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iMac iCloud Photos not syncing; need setup help

I use a 24-inch 2023 model iMac with Tahoe 26.1 installed. This morning, looking for a particular photo, I realised that many were missing.

Presently, I hold all my photos on an external hard drive, and this tells me they amount to 3,800. However, on iCloud, it tells me it has over 6000 photos and the same on my ipad

I want to revert to accessing all my photos through iCloud and discard the external hard drive storage for the moment. I have spent a while going through various scenarios as to how to do this and am a little perplexed.

When I open up settings on my iMac and click on iCloud, then Photos, it shows the button as on to allow sync but this must not be happening for some reason

I want my iMac to access the icloud photos in the same way my iPad does (I guess) Am I missing something?

Can someone tell me in layman terms how I set my Mac up so that it accesses iCloud?

iMac 24″, macOS 26.1

Posted on Nov 22, 2025 7:59 AM

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Answer 1

Top-ranking reply

Richard.Taylor

Level 6

16,777 points

Nov 22, 2025 10:18 AM in response to Vandestadt

Unlike an iPad, a Mac can have several different Photos Libraries. Only one, the System Library, connects to iCloud. So one possibility is that you're looking at the wrong Library.

First, we need t double check that your external drive is correctly formatted in either APFS format or Mac OS Extended (Journaled) format. Other wise the Library can be corrupted, and Photos will refuse to use it. Is the format OK? See this for more info:

Move your Photos library to save space on your Mac - Apple Support

You can see what Photos Libraries you have by opening the Library Chooser. Close Photos and option click the Photos icon to get this:

You can see which Libraries you have, where they are, and which one is the System Library.

The System Library is set in Photos' Settings>General

iCloud is controlled by Photos' Settings>iCloud

You can just create a new empty Library, make it the System Library, connect it to iCloud, and then just wait for it to fill from iCloud. That could be the easiest thing.

Let us know how it goes…

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