Sync and cloud storage

What is cloudphotod?

cloudphotod is the macOS agent for iCloud Photos. Uploads and downloads of your photo library show under it. photolibraryd handles the library itself, and Photos has a Pause button for uploads.

Process: cloudphotodAlso seen as: photolibraryd, photoanalysisdMade by AppleApplies to: macOS 14 Sonoma and later. Checked on macOS 27.2.Checked: 1 November 2026

Short answer

Part of macOS. It does all iCloud Photos sync, so its traffic is your photos and videos going up and down.

Block with care

Blocking it stops iCloud Photos sync on this Mac. Photos already here stay. Use Photos' Pause button instead to stop uploads for a day.

Path: /System/Library/PrivateFrameworks/CloudPhotoLibrary.framework/Versions/A/Support/cloudphotod /System/Library/PrivateFrameworks/PhotoLibraryServices.framework/Versions/A/Support/photolibraryd
launchd label: com.apple.cloudphotod com.apple.photolibraryd
Signing identifier: com.apple.cloudphotod com.apple.photolibraryd

What it is

The man pages describe three agents. cloudphotod is “responsible for all iCloud Photos activity”.

photolibraryd “handles all photo library requests”. photoanalysisd handles background processing for Memories, People and search.

Of these three, only cloudphotod is described as doing iCloud Photos sync. The man pages don't say that the other two use the network.

Why it uses the network

Uploads of new photos and videos. With iCloud Photos on, new items upload to iCloud.
Downloads from your other devices. Items from your iPhone or other devices download to this Mac.
Originals on demand. Apple says that with Optimize Storage, the device keeps space-saving versions. You can download originals when you need them.

How much is normal

A large upload after an import is usual. Apple says that a big library can need to sync overnight, and that some larger files take longer.

Apple says that syncing pauses in Low Data Mode and in Low Power Mode. It also pauses below 20 percent battery, when the device needs to cool down and when iCloud storage is full.

Look closer if it never finishes. The Photos library status at the bottom of All Photos says why sync is paused.

When it uses a lot, and why

An import. Importing from a camera or a card uploads every new photo and video in full. 4K video makes this large quickly.
A first sync. Turning on iCloud Photos on a Mac, or signing in on a new Mac, syncs the whole library.
Download Originals to this Mac. Apple says that this option keeps the original, full-size photos and videos in iCloud and on your Mac. Every original then downloads.

Is it safe to block?

Block with care

Blocking it stops iCloud Photos sync on this Mac. Photos already here stay. Use Photos' Pause button instead to stop uploads for a day.

What breaks if you block it

New photos and videos on this Mac don't upload, and photos from your other devices don't arrive.
With Optimize Storage, originals that are only in iCloud can't download.
Shared Library changes stop syncing.

Blocking means a firewall rule that refuses its connections. Don’t quit or disable a macOS process to save data: macOS starts it again, and other features depend on it.

Reduce its use

To pause uploads for one day, open Photos. Click Library, then All Photos.
Scroll to the bottom and click Pause. Apple says that Pause stops uploads for one day.
On a hotspot or a capped plan, turn on Low Data Mode. Choose Apple menu › System Settings › Wi-Fi. Click Details next to the network, then turn on Low Data Mode. Apple says that iCloud Photos pauses in Low Data Mode.
Do big imports on your usual network, on power.
Don't turn off iCloud Photos to fix a slow sync. Apple says that this restarts the syncing process.
Don't quit cloudphotod in Activity Monitor. macOS starts it again.

See how much it uses

Open Activity Monitor from Applications › Utilities. Click Network.
Type cloudphotod in the search field. The Sent Bytes and Rcvd Bytes columns show what it moved since it started.
In Terminal, watch only this process. Press d to show the change per second, and q to quit.
```
nettop -p 'cloudphotod' -P
```

With Kilobat

In the Kilobat app list, search for cloudphotod. Its row shows the live rate and what it moved today.
In Connections, click the ⓘ button on one of its rows. The popover shows this page’s short answer, without going online.
In Terminal, ask the same question. Add --json for scripts and agents.
```
kilobat explain 'cloudphotod'
```
Show its traffic over one day.
```
kilobat bandwidth 'cloudphotod' day
```
Through MCP, an AI agent asks explain_connection with the process name. It gets the same facts.

The live view and the explanations are free. History in the app needs Kilobat Pro. Blocking needs Pro and the network filter: see the network filter, Protection and the hotspot data saver.

Hosts it contacts

Apple and the maker document these hosts for this feature. A process can also contact others; Kilobat’s Connections tab shows what it actually opens on your Mac.

*.icloud-content.comAn Apple domain for iCloud services. Large uploads and downloads of iCloud content, such as files and photos, can go to hosts under it.Apple →*.icloud.comApple's iCloud domain. Apple lists *.icloud.com for iCloud services; specific hosts under it have their own pages.Apple →

Questions

Why is photoanalysisd busy when I am offline?

Its work is analysis of the library on the Mac. The man page describes it as background processing, not as sync.

How long does Pause last?

Apple says that Pause stops uploads for one day.

Is photolibraryd using my internet?

The man page says only that it handles photo library requests. iCloud Photos sync is cloudphotod's job.

Sources

cloudphotod(8), photolibraryd(8) and photoanalysisd(8), man pages installed with macOS 27.2
launchd property lists com.apple.cloudphotod and com.apple.photolibraryd, macOS 27.2
Apple Support: Set up and use iCloud Photos
Apple Support: If your iCloud Photos aren't syncing or syncing with iCloud is paused
Apple Support: Use Apple products on enterprise networks

Checked on 1 November 2026.