iCloud Drive Not Syncing on Mac? 10 Fixes

A file sits at "Waiting to upload" for an hour, or the same document refuses to appear on your other devices. iCloud Drive fails quietly — there's no error dialog, just a spinner that never finishes. Work through these ten fixes in order: the first four take two minutes, and the last one tells you exactly what's wrong.

Fixes 1–4: the two-minute checks

1. Check Apple's side first. Open apple.com/support/systemstatus and look for a green dot next to iCloud Drive. Outages are rare but real, and no amount of local fiddling fixes one.
2. Check whether it's actually stuck. Click iCloud Drive in Finder's sidebar. A progress pie next to a file or folder means transfer is happening — a big first upload or a slow connection can legitimately take hours. Stuck means no movement at all across many minutes.
3. Confirm you're really online. Load any website. Hotel and café Wi-Fi often sits behind a login page that blocks background traffic even when the Wi-Fi icon looks fine.
4. Check your iCloud quota. Open System Settings → your name → iCloud. If the storage bar is full, uploads stop silently — nothing syncs until you free space or upgrade.

Fixes 5–7: restart the machinery

iCloud Drive on the Mac is run by a background daemon called bird. When it wedges, restarting it clears more sync problems than anything else.

1. Restart the Mac. Unglamorous, effective — it restarts bird and every network service in one move.
2. Restart just the sync daemon. If a reboot is inconvenient, kill bird from Terminal; macOS relaunches it automatically within seconds, so there's nothing to undo:

# restart the iCloud Drive sync daemon (it respawns on its own)
killall bird

7. Toggle iCloud Drive off and on. In System Settings → your name → iCloud → iCloud Drive, turn off Sync this Mac (on Ventura, turn off iCloud Drive itself), wait ten seconds, and turn it back on. Your files stay safe in iCloud; the Mac re-downloads its local copies, which forces a fresh sync pass.

Fixes 8–9: the account-level escalations

8. Fix the clock. A wrong system clock breaks iCloud authentication in strange ways. In System Settings → General → Date & Time, make sure Set time and date automatically is on.
9. Sign out of iCloud and back in. System Settings → your name → Sign Out. macOS asks whether to keep copies of iCloud data on this Mac — say yes. Sign back in with the same Apple ID. This rebuilds the account state from scratch and resolves the "one Mac out of three won't sync" cases that nothing else touches. Budget time: everything re-syncs afterwards.

Fix 10: watch the sync log live

When the generic fixes fail, stop guessing. Apple ships a diagnostic tool for iCloud Drive called brctl, and its live log shows exactly what the sync engine is doing — or the error it keeps hitting:

# stream iCloud Drive sync activity; press Ctrl+C to stop
brctl log --wait --shorten

Leave it running, then add a small test file to iCloud Drive in Finder. You should see lines scroll as it uploads. If the log sits silent, the daemon isn't even trying (go back to fixes 6–9). If it scrolls repeating errors — quota, auth, or a specific file path it chokes on — you have your culprit. A single un-uploadable item (often a file with an extremely long name, or one locked by an app) can jam the queue; move the named file out of iCloud Drive and watch whether everything behind it starts flowing.

See also: how to keep files local instead of in iCloud.

One more check: is it just this file?

If exactly one item won't sync while everything else flows, the file is the problem, not the pipe. Duplicate it (⌘D), delete the original, and see whether the copy uploads. And if items sit permanently at "waiting to upload", that specific state has its own playbook — see fixing files stuck waiting to upload.