cloudd

Something is syncing. A large upload, many small files, or a folder that changes constantly (for example a project folder with build output inside iCloud Drive) keeps them busy.

You can check sync progress in Finder: the iCloud Drive item in the sidebar shows a progress indicator while files upload or download.

Let a large sync finish while the Mac is on a good network connection. Keep folders that change constantly, such as code dependencies and build output, outside iCloud Drive.

Quitting cloudd or bird in Activity Monitor does not stop syncing for long, because macOS starts them again. Change what is syncing instead, in System Settings, under your Apple Account, iCloud.

Finder can show the iCloud status of every file, which tells you what cloudd and bird are working on.

1. Open a Finder window and click iCloud Drive in the sidebar.
2. Choose View > as List, then choose View > Show View Options and select iCloud Status.
3. Look for files marked Waiting to Upload, or a pie chart icon that fills in as a file transfers.
4. Check the iCloud Drive item in the sidebar. A pie chart next to it shows the overall progress for files going to and from iCloud Drive.
5. In Activity Monitor, click the Network tab and find cloudd and bird. Their Sent Bytes and Rcvd Bytes show whether data is still moving.

If syncing seems to run for days without finishing, work through these in order. Signing out of iCloud and back in is a heavier step than it looks, since it can mean syncing everything again, so leave it for last or for when Apple Support suggests it.

• Look for files marked Out of Space in Finder. That means your iCloud storage is full, and those files cannot upload until you free space or add storage.
• Check your network. A slow or unstable connection makes syncing take much longer.
• Look for a folder in iCloud Drive that changes constantly, such as a code project, and move it outside iCloud Drive.
• Check Apple's System Status page to see if iCloud services are having problems.
• Restart the Mac, which restarts cloudd and bird cleanly.

If the work you expect is photo syncing and it seems stuck, it may be paused on purpose. Apple says iCloud Photos syncing can pause for reasons such as Low Data Mode, Low Power Mode, battery or performance optimization, or a poor network connection. That work is handled by cloudphotod rather than cloudd or bird.

cloudd is the system process behind CloudKit, the service apps use to store and sync their own data in iCloud. When an app you use syncs its settings or records, cloudd does the transfer.

bird backs iCloud Drive, the files and folders you see in Finder. You may also see a process named com.apple.CloudDocs.iCloudDriveFileProvider next to it, which connects iCloud Drive to Finder. If Finder shows files uploading, bird is the one to watch. If nothing is moving in iCloud Drive but cloudd is busy, an app is syncing its data.