What Is cloudd on Mac? CloudKit and High CPU

cloudd appears in Activity Monitor, sometimes more than once. You know iCloud is involved, but Finder may not show a file transfer and none of your open apps says it is syncing. What is the process actually doing?

The short answer: cloudd is the macOS service behind CloudKit, which apps can use to store and synchronize data through iCloud. It is not another name for bird, the process associated with iCloud Drive file syncing. A busy cloudd points you toward app data and sync activity, but it does not identify a specific app or prove that syncing is stuck.

Keep cloudd activity in perspective

If iCloud-related activity makes the Mac feel busy, MacStats keeps overall CPU and RAM readings in the menu bar. Click the MacStats menu bar item for Top CPU and Top RAM in the Detailed dashboard. The user-owned cloudd instance we observed can appear there when it is one of the busiest processes.

Monitoring is free on Apple silicon Macs running macOS 13 or later. MacStats Pro adds the Process Explainer to put an unfamiliar process reading into plain English. Use Activity Monitor's All Processes view for a complete list of running instances, and the affected app to check its sync progress.

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CloudKit is not just the iCloud Drive folder

An app can synchronize its own records without putting a document in the iCloud Drive folder you browse in Finder. Apple's Core Data and CloudKit documentation describes app changes being uploaded and delivered to other devices, with that work occurring in the background.

The local manual identifies cloudd as the service backing CloudKit:

man cloudd

This gives you the useful distinction: a Finder file-transfer indicator is not a complete view of all iCloud-related work. Checking an iCloud Drive folder alone cannot tell you whether every app has finished syncing its data.

For the file-syncing side, see our bird guide. fileproviderd is another separate service, coordinating File Provider extensions. Treating all three names as interchangeable makes troubleshooting less precise.

If you see two cloudd processes

On our test Mac, running macOS 27.0.1, we found two copies: one owned by the logged-in user and another owned by root. Both used this executable:

/System/Library/PrivateFrameworks/CloudKitDaemon.framework/Support/cloudd

You can check the running instances without changing anything:

ps -axo user,pid,comm | grep '/cloudd$'

The account matters. Two copies under different owners are not, by themselves, evidence of a duplicate installation or malware. They also explain why a monitor limited to your own processes may show fewer instances than Activity Monitor's All Processes view.

This is a measured example, not a rule that every Mac must always run exactly two copies. Private framework paths and service arrangements can change with macOS versions. Check the details on your own machine if the identity is in doubt.

How to investigate high CPU use

Start by separating three questions: is CPU use sustained, is any app's data failing to synchronize, and is the Mac actually struggling?

In Activity Monitor, select CPU and sort by % CPU. Watch whether the activity settles. A brief spike and a service that stays busy for an extended period are different patterns, even if the largest number looks similar.

Then check the apps whose iCloud data you have recently changed. Does an edit made on one device arrive on the other? Is there an error inside the app? A concrete sync failure is a better lead than guessing from the process name. Check the affected app's own help for its sync controls; do not assume every app has a Pause button.

If several iCloud services appear to be failing, check your connection and Apple System Status before changing your account settings. That page reports service status; it does not diagnose your Mac's CPU use.

If activity remains disruptive, save your work, restart and observe again. Keep track of which app or change reproduces the problem. That gives its developer or Apple support something more specific to investigate than “cloudd was high.”

Why quitting it is not a sync repair

The manual does not offer a user-facing configuration for cloudd and says not to run it manually. It is a system-managed service, not an app whose documents you can save and close in the usual way.

Avoid deleting CloudKit support folders, signing out of iCloud or disabling several sync services merely to make the process disappear. Those are broader changes to your data setup, and a quieter process after a reset does not establish what caused the original load.

If the affected app reports a specific error, follow its documented recovery procedure. If there is no error and the work is progressing, observation is often more useful than repeatedly interrupting the service.

For network activity that seems unrelated to a foreground app, nsurlsessiond is another name you may encounter. Our background-process hub maps these roles together.

Frequently asked questions

What is cloudd on my Mac?

It is the service backing CloudKit, Apple's framework for app data stored and synchronized through iCloud. To read its local manual, run man cloudd in Terminal.

Is cloudd the same as bird?

No. cloudd backs CloudKit app data. bird is associated with iCloud Drive file syncing. A problem involving iCloud does not make them the same service.

Why are there two cloudd processes?

Our test Mac had one under the logged-in user and one under root. Check the owner and executable path before treating multiple instances as suspicious. The number of running instances can vary.

How can I tell which app is making cloudd busy?

The process name and CPU reading alone do not identify the app. Look for a reproducible change or sync error in an app using iCloud, and check whether its data reaches another device.