The fastest way to back up a Mac is Time Machine, which comes built in

Time Machine is Apple's automatic backup system, and it comes with every Mac. It backs up your entire computer — documents, photos, applications, settings — to an external hard drive or network storage. Once you plug in a drive and turn Time Machine on, it runs in the background every hour without you doing anything else. If something goes wrong, you can restore your whole Mac or just pull out individual files.

Time Machine is not the only way to back up, but it is the simplest for most people because it requires almost no setup and no ongoing attention. The trade-off is that it only works if you have an external drive connected or a compatible network storage device available.

Key Takeaways

  • Time Machine backs up your entire Mac automatically to an external drive and stores multiple versions so you can recover files from any point in the past.
  • You need an external hard drive or compatible network storage device that is at least as large as your Mac's storage to use Time Machine effectively.
  • iCloud can back up documents and photos but does not back up applications or system settings, so it works best alongside Time Machine rather than instead of it.
  • The first Time Machine backup takes several hours depending on how much data you have, but later backups only save changes and run much faster.
  • You should test your backup by restoring a file or two before you actually need it, so you know the process works when something goes wrong.

Setting up Time Machine with an external drive

Plug an external hard drive into your Mac using a USB, Thunderbolt, or USB-C cable — whichever port your Mac has. The drive should be empty or contain only files you do not mind losing, because Time Machine will erase it during setup. If the drive is new, your Mac will usually prompt you to use it for Time Machine right away. Click Use as Backup Disk if you see that prompt.

If you do not see a prompt, open System Settings (or System Preferences on older Macs), click General in the sidebar, then click Time Machine. Click the button that says Add Backup Disk or Select Backup Disk, choose your external drive from the list, and click Use Disk. Your Mac will erase the drive and start backing up immediately.

The first backup can take several hours if you have a lot of files — anywhere from 2 to 8 hours depending on how much data is on your Mac and how fast your drive is. Do not unplug the drive or put your Mac to sleep during this first backup. After that, Time Machine backs up only the files that changed since the last backup, so later backups usually finish in minutes.

Choosing the right external drive for Time Machine

You need an external hard drive that is at least as large as your Mac's storage. If your Mac has 256 GB of storage, get a drive that is 256 GB or larger. A 500 GB or 1 TB drive gives you room to store multiple versions of your files going back weeks or months, which is more useful than a drive that is barely large enough.

Any external hard drive works with Time Machine — you do not need a special "Mac backup drive." Common options include Western Digital, Seagate, LaCie, and Samsung. Solid-state external drives (SSDs) are faster than traditional spinning hard drives but cost more. For most people, a traditional external hard drive is fine and costs less.

If you want to back up multiple Macs to the same drive, you need a drive that is large enough for all of them. Time Machine creates a separate backup folder for each Mac, so a 2 TB drive can hold backups of two Macs with 1 TB of storage each, for example.

Using iCloud to back up documents and photos

iCloud is Apple's cloud storage service, and it backs up certain types of files automatically if you turn it on. iCloud backs up documents you create in Apple's apps (Pages, Numbers, Keynote), photos in the Photos app, and some settings. It does not back up applications, your entire system, or files stored outside of Apple's ecosystem.

To turn on iCloud backup, open System Settings, click your name at the top of the sidebar, then click iCloud. Toggle on iCloud Drive to back up documents, and toggle on Photos to back up your photo library. You get 5 GB of free iCloud storage; beyond that, you pay a monthly fee. A 50 GB plan costs $0.99 per month, 200 GB costs $2.99 per month, and 2 TB costs $9.99 per month.

iCloud is useful for keeping your documents and photos safe and synced across your devices, but it should not be your only backup. Use iCloud alongside Time Machine so that your entire Mac is protected.

Restoring files from a Time Machine backup

If you need to recover a file you deleted or that got corrupted, open the folder where the file used to be. Click the Time Machine icon in the menu bar at the top right of your screen, then click Enter Time Machine. Your screen will show a timeline of backups on the right side. Click the date when you know the file still existed, and your Mac will show you what that folder looked like on that date.

Find the file you want to restore, click it, and click Restore. The file will come back to its original location. If you want to restore your entire Mac from a Time Machine backup — for example, after replacing a broken hard drive — restart your Mac while holding Command-R to enter Recovery Mode, then choose Restore from Time Machine Backup.

Restoring a single file usually takes a few seconds. Restoring your entire Mac can take an hour or more depending on how much data you have. During a full restore, your Mac will restart several times and show a progress bar.

What to do if Time Machine stops working

If Time Machine has not backed up in several days, open System Settings, go to Time Machine, and check that your backup disk is still connected and selected. Sometimes a drive disconnects accidentally or your Mac forgets which drive to use. Unplug the drive, wait 10 seconds, and plug it back in.

If Time Machine says your backup disk is full, you have two options: delete the oldest backups to make room, or connect a larger drive. Time Machine automatically deletes the oldest backups when the disk gets full, but if you want to speed that up, open Time Machine settings, click Options, and click the minus button next to your backup disk to remove old backups manually.

If Time Machine is stuck on a backup that will not finish, force-quit Time Machine by pressing Command-Option-Escape, selecting Time Machine, and clicking Force Quit. Then unplug your backup drive, wait 30 seconds, and plug it back in. Time Machine should start a new backup on the next hour.

Backing up to network storage instead of an external drive

If you do not want to keep an external drive plugged into your Mac all the time, you can back up to a network storage device instead. This is a drive or device connected to your home network that your Mac can reach over Wi-Fi or ethernet. Time Machine will back up whenever your Mac is on the same network as the storage device.

Common network storage options include a Time Capsule (Apple's own network backup device, though it is no longer sold new), a Synology NAS, or a QNAP NAS. These devices are more expensive than an external drive but let you back up multiple computers and access your backups from anywhere on your network.

To set up Time Machine with network storage, open System Settings, go to Time Machine, click Add Backup Disk, and select your network device from the list. The setup process is the same as with an external drive.

Frequently Asked Questions

Can I use the same external drive to back up two different Macs?

Yes. Time Machine creates a separate backup folder for each Mac, so one drive can hold backups of multiple computers. Make sure the drive is large enough for all of them — if you have two Macs with 500 GB each, use at least a 1 TB drive.

What happens if I unplug my backup drive while Time Machine is running?

Time Machine will pause and resume the backup the next time you plug the drive back in. You will not lose the backup that was already saved, but the current backup will not finish until you reconnect the drive. Avoid unplugging during backups if you can, but it is not dangerous.

Does Time Machine back up my passwords and login information?

Yes. Time Machine backs up everything on your Mac, including passwords stored in Keychain, browser data, and login information. When you restore from a Time Machine backup, all of that comes back too.

How often should I test my backup to make sure it works?

Test your backup at least once when you first set it up, and again every few months. Restore a single file you do not need to make sure the process works. That way, if something goes wrong, you will know before you actually need to recover important data.

Can I back up my Mac to cloud storage like Google Drive or Dropbox instead of an external drive?

Not with Time Machine — it only works with local drives or network storage. You can manually copy files to Google Drive or Dropbox, but that is not the same as a full system backup. For a complete backup, use Time Machine with an external drive or network storage.