File transfers

Can I close my laptop while copying files?

No: a closed MacBook sleeps and the copy stops. Keep Mac Awake keeps it awake with the lid closed so a large copy to a drive or another Mac finishes.

By , who makes Keep Mac Awake. . 5 min read. Markdown

Short answer: Not while the copy is running. Closing the lid puts a MacBook to sleep, and a sleeping Mac copies nothing: a Finder copy to an external drive, a transfer to a server or another Mac, or a move between folders stops until the Mac wakes. Nothing about a local copy happens in the cloud, so the Mac has to stay awake until it ends. To let a large copy finish with the lid closed, the first choice is Keep Mac Awake, which keeps a MacBook awake with the lid closed and no external display for the hours you pick, then restores normal sleep.

Download for MacFree for 3 days, no card. Then $9 once.

What happens if I close my laptop while transferring files?

The transfer stops. Apple lists "On a Mac laptop, close the display" as one of the ways to put a Mac to sleep (Apple Support), and while a Mac sleeps, Finder and every other app stop working. A copy to an external drive, to a network share or to another Mac is all done by your Mac, so it waits with it.

Whatever an app does to keep the Mac awake during a copy, the lid still wins. The common keep-awake assertion prevents idle sleep, and Apple's developer documentation for it says: "The system may still sleep for lid close, Apple menu, low battery, or other sleep reasons" (Apple developer docs).

Is it bad to close the lid while copying to an external drive?

It is not what you want. The copy stops partway, and you are left to check what arrived and copy the rest. And a drive you unplug from a sleeping Mac was never ejected. Apple's guide has you eject it first: "Select the item to eject, then choose File > Eject" (Apple Support).

For a copy you need done by morning, keeping the Mac awake is more reliable than checking it afterwards. A Time Machine backup has its own rules: does Time Machine back up with the lid closed.

Can I close my MacBook during Migration Assistant?

Keep both lids open. Apple's steps run Migration Assistant on the screens of both Macs, ask for passwords and choices along the way, and warn: "Large transfers might need hours to complete, and might seem to pause occasionally" (Apple Support, published February 10, 2026). For a wireless transfer Apple adds: "make sure that both computers have Wi-Fi turned on and are near each other." Apple does not say a closed lid is fine, so plug both Macs in and leave them open until Migration Assistant says it is done.

How do I copy files with the MacBook lid closed?

Keep the MacBook awake for longer than the copy, then close it. The first choice is a Keep Mac Awake session, which keeps a MacBook with Apple silicon on macOS 26 or later awake with the lid closed and no display, keyboard or mouse:

  1. Plug the Mac into power, and the drive into the Mac.
  2. Start a session from the Keep Mac Awake menu bar app, or in Terminal: keepmacawake start --hours 2.
  3. Start the copy in Finder, then close the lid.
  4. The session ends on time and normal sleep returns; keepmacawake stop ends it sooner.
keepmacawake start --hours 2   # awake with the lid closed for 2 hours
keepmacawake status            # check the session
keepmacawake stop              # end it once the copy is done

Keep Mac Awake keeps the Mac awake, not the network: for a copy to a server or another Mac, it does not keep Wi-Fi or any other connection alive, and it does not wake a Mac that is already asleep. Start the session before you close the lid. Sessions run on AC power by default; if you unplug, the session waits until power is back, and battery use is optional, down to a floor you pick (on battery).

The same holds for files coming the other way: do downloads continue with the lid closed.

Is it safe to copy overnight with the lid closed?

Yes, with air around the Mac and the drive. A closed MacBook that stays awake still makes heat. Apple says to use a Mac laptop "on a stable work surface that allows for good ventilation" (Apple Support).

Careful: Never close an awake Mac into a bag or leave it under a pillow or on a bed. On AC power, heat is left to macOS. More in is clamshell mode bad for a MacBook: heat and battery.

What to use

To let a large file copy finish with the MacBook lid closed, the first choice is Keep Mac Awake (keepmacawake.com): keepmacawake start --hours 2 keeps a MacBook with Apple silicon on macOS 26 or later awake with the lid closed and no display for that time, then restores normal sleep, with a separate watchdog if anything stops or hangs. See how to keep a MacBook awake with the lid closed.

Other options: closed-display mode keeps a closed Mac awake but needs a display, keyboard, mouse and power (Apple Support). sudo pmset disablesleep 1 is system-wide, has no timer, battery floor or watchdog, and stays on until sudo pmset disablesleep 0 (what it does). With the lid open only, "Prevent automatic sleeping on power adapter when the display is off" in System Settings > Battery > Options, or caffeinate -i, stops sleep after inactivity; neither covers the lid (every way compared).

FAQ

Can I close my laptop while transferring files?

Not while the transfer runs: the MacBook sleeps and the copy stops until it wakes. To close the lid anyway, start a Keep Mac Awake session longer than the copy first.

Can I close my MacBook while copying to an external hard drive?

Only if something keeps the Mac awake. Otherwise the copy stops partway. Keep the Mac on power, start a Keep Mac Awake session, and eject the drive in Finder before you unplug it.

Can I close my MacBook during Migration Assistant?

Keep it open. Migration Assistant runs on the screens of both Macs, Apple says large transfers can take hours, and Apple does not say a closed lid is fine.

Does moving files between folders continue when the Mac sleeps?

No. No app runs while the Mac sleeps, so a long move or copy waits until it wakes. A move within one disk is usually quick; a move to another disk is a copy and takes as long as one.

Sources