What is cloudd on a Mac?

27 October 2026 · 5 min read

cloudd is the macOS program that syncs app data with iCloud. When an app keeps notes, reminders or other data in iCloud, cloudd sends the changes up and brings the changes from your other devices down. It is normal for it to be busy after you sign in to iCloud, or after a large change, and it quiets down once the sync catches up. It belongs to macOS, and you do not need to remove it.

The name is short for cloud daemon, and a daemon is a background program with no window.

What cloudd does

iCloud is not one thing. Your files in iCloud Drive are handled by bird, which What is bird on a Mac? iCloud Drive’s sync process covers. Everything else that apps keep in iCloud goes through cloudd. Foreman’s one-line description is: syncs app data with iCloud.

Apps use a part of iCloud called CloudKit to store their own data, and cloudd does the talking. That can include:

notes, reminders and similar records kept by Apple’s apps
data that apps from other developers store in iCloud with CloudKit
the databases of apps that use iCloud to keep several devices in step

You do not choose when it works. An app saves a change, and cloudd sends it on. Another device saves a change, and cloudd fetches it.

Why it is busy

cloudd is busy when there is a lot of data to compare or move. Typical triggers:

Signing in to iCloud on a Mac. The first sync has to catch up with everything.
Turning on iCloud for an app. The app’s whole data set is sent up or pulled down.
A big change. Importing thousands of items, restoring a backup, or editing a large amount in one go.
An app that saves very often. Each small save is a change to send.
A poor connection. Retrying makes it look busy for longer.
A macOS update or a new Mac, where apps check their data again.

Syncing needs a working connection, so if the Mac is on weak Wi-Fi or a connection that drops, work piles up. If you want to see what else is using the network, How to see which app is using your network on a Mac shows how.

What to check

The connection. Load a web page. A failing connection is a common reason sync looks stuck.
Signed in. In System Settings, click your name at the top and check you are signed in. If macOS shows a message asking you to sign in again, do that, because sync cannot proceed without it.
iCloud storage. If your iCloud storage is full, uploads stop and cloudd keeps trying. The iCloud page in System Settings (click your name, then iCloud) shows how much is used.
Which app. Apps that sync through iCloud are listed on the same iCloud page, each with its own switch. If one app has been syncing for days, turning it off and on again can start it fresh, but only do that if you are sure the data is also safe elsewhere.
Wait. A big first sync takes hours, not minutes, and it is best to leave the Mac awake and online.
Restart. If cloudd has been busy for days with nothing new, restart the Mac.

Be careful with advice that tells you to delete iCloud files or caches by hand. Removing the wrong folder can lose data that has not finished uploading.

Should you end cloudd

You can, and macOS will start it again, because apps need it. Ending it pauses sync for a short time at most. It is not an off switch. If you do not want an app’s data in iCloud, turn that app off in the iCloud settings; if you do not want iCloud at all, sign out in System Settings, after making sure you have your data somewhere else.

If you are chasing a slow Mac and cloudd looks busy, it is worth asking whether it is busy because of a sync that is genuinely working, which is fine, or because it has been stuck for days, which is not. How to end a background process on a Mac describes the safe way to end processes in general.

Seeing it in Foreman

Foreman lists it on the Processes page as “iCloud sync”, with cloudd beside it in grey. Click the CPU or Network column to sort and it rises to the top while it works. You will often see “iCloud Drive” (bird) and “Cloud files” (fileproviderd) busy at the same time, since they belong to the same family of sync programs. Looking at the three together shows quickly whether iCloud as a whole is the busy thing.

There are often two copies of cloudd: one under your account and one owned by the system, and Foreman’s All Processes page, with its User column, shows which is which. Foreman can put the one under your account in Efficiency Mode, which runs it at background priority so syncing carries on more slowly. It does not offer that for the system’s copy. Otherwise, what it gives you is the plain name, a one-line explanation and the numbers, so you can decide whether iCloud is what is slowing things. If the Mac is slow and the sync rows are quiet, look at the apps at the top of the list; How to find out what’s running in the background on your Mac shows how.

When to worry

Mostly you should not. Look closer if cloudd is busy for days at a time, if an app’s data does not match on your devices, or if you see sign-in or storage messages. Check the connection, sign-in and iCloud storage first. After that, restart the Mac, and then ask Apple Support if the same problem returns.

Quick answers

Is it a virus? No. It is part of macOS.
What is it syncing? App data kept in iCloud, apart from iCloud Drive files.
Will it stop? Yes, once the sync has caught up.
Can I turn it off? Turn off iCloud for an app, or sign out, in System Settings. Do not try to remove the process.

You can do all of the above without extra software. Foreman is $12 once and free for 24 hours if you want to watch the row.