Foreman
Download Buy $12

What is bird on a Mac? iCloud Drive's sync process

· 5 min read

bird is the program that syncs iCloud Drive. It uploads the files you add or change in iCloud Drive and downloads the ones that changed on your other devices, so the same files appear everywhere. It is busy when there is a lot to upload or download, usually after a big change, and it settles on its own. The thing to check first is your internet connection.

The name has nothing to do with the social network or with animals. It is a short internal name Apple has used for this sync program for years.

What bird does

iCloud Drive keeps a folder of files in step across your Mac, iPhone, iPad and the web. Foreman’s one-line description is plain: it syncs iCloud Drive files. Behind that line, bird does several things:

  • It notices when a file in iCloud Drive changes on the Mac and sends the change up.
  • It notices when a file changed elsewhere and brings it down.
  • It keeps track of which files are downloaded and which are only listed.

It works alongside two other processes. cloudd syncs app data with iCloud and is covered in What is cloudd on a Mac?. fileproviderd connects cloud storage to Finder, which What is fileproviderd on a Mac, and why is it busy? explains. When you move a large folder into iCloud Drive, you may see all three working.

Why it is busy

bird uses processor time and network while there is something to move. The usual reasons:

  • Moving a big folder into iCloud Drive. Every file has to go up, and bird works through them.
  • A large download. Opening a folder with many files that changed on another device pulls them down.
  • Signing in, or turning iCloud Drive on. The first sync has to compare everything.
  • Files that change constantly. A project folder, a database or an app’s working files kept in iCloud Drive give bird new work again and again. Folders like that work better outside iCloud Drive.
  • A slow or interrupted connection. The work takes longer, so bird looks busy for longer.

Many small files are harder on it than a few big ones, because each file has its own bookkeeping.

What to check

Go through these in order.

  1. The connection. Syncing needs a working internet connection. If Wi-Fi is weak or drops, bird keeps retrying. Try a web page. If you need to see which app is using the network, How to see which app is using your network on a Mac shows how.
  2. Signed in. Open System Settings, click your name at the top of the sidebar, then click iCloud. Check that iCloud Drive is turned on and that you are signed in with the right account.
  3. Free space on the iCloud account. If iCloud storage is full, uploads stop and sync can look stuck. The bar at the top of the same iCloud page shows how much is used.
  4. Free space on the Mac. A nearly full disk gets in the way of downloads. System Settings, General, Storage shows how much is free.
  5. Finder. In Finder, files that are not fully on your Mac show a cloud symbol, and files in the middle of a transfer show progress. That tells you which files it is working on.
  6. Wait. A large sync can take hours. Leave the Mac awake and online.

What helps

  • Leave the Mac on and connected while a big sync runs. A laptop that sleeps part way through pauses the work.
  • Move files in smaller batches instead of a whole archive at once.
  • Keep fast-changing files out of iCloud Drive. Source code, virtual machines and databases are better kept somewhere that does not try to sync each change.
  • Restart the Mac if bird has been busy for days with nothing new to sync. That clears most stalls.

Should you end bird

You can end it, and macOS will start it again, because it is part of how the Mac works. Ending it pauses the sync for a moment at best. If it has been stuck, ending it and letting it restart can nudge it along, but a restart does the same job more cleanly. It is not a way to turn iCloud Drive off. For that, use the iCloud Drive setting in System Settings.

Seeing it in Foreman

Foreman lists it on the Processes page as “iCloud Drive”, with bird beside it in grey. The CPU and Network columns show how much it is using now, and you can click either to sort. Foreman has a Network column for each process, so you can compare bird with a browser or a backup, and the total above the column shows how much the whole Mac is moving.

That is enough to answer the usual question: is iCloud Drive the thing slowing the Mac down, or the thing using my connection, or is it something else? If bird is quiet and the Mac is slow, look at the apps at the top of the list.

If you would rather iCloud Drive took less of the Mac while you work, Foreman can put bird in Efficiency Mode, because bird runs under your own account (the User column shows this). It then runs at background priority, with its disk use turned down, and the sync carries on more slowly. Turn Efficiency Mode off and it runs at full speed again at once. Foreman does not add or remove files in iCloud Drive. How to find out what’s running in the background on your Mac has the wider approach.

When to worry

Usually you need not. Look closer if bird is busy for days, the same files never finish, or you see sync errors in Finder. Then check iCloud storage, free space on the Mac, and the connection, in that order, and restart. If a particular file never syncs, try moving it out of iCloud Drive and back.

Quick answers

  • Is it a virus? No. It is part of macOS.
  • Why is it using the network? It is uploading or downloading iCloud Drive files.
  • Will it stop? Yes, when the sync is done.
  • Can I turn it off? Turn off iCloud Drive in System Settings if you do not want it.

The steps above work without extra software. Foreman is $12 once and free for 24 hours.