Time Machine is the backup most Mac owners never turn on — until a spilled coffee or a dead SSD makes it the only thing that matters. It is built into every Mac, it is free, and once it is running it protects your files every hour without you thinking about it. This guide walks through choosing a drive, setting it up, restoring your files, and the one backup you should always make before selling or trading in a Mac.
What you need
- An external drive — USB-C or USB-A SSD or hard drive. Aim for at least double your Mac's storage (a 256GB Mac wants a 512GB or 1TB backup drive) so Time Machine can keep weeks of older versions, not just one copy.
- Ten minutes for setup. The first backup runs in the background and can take a few hours; every backup after that only copies what changed and usually finishes in minutes.
A NAS or shared network drive also works, but a plain external SSD plugged in over USB is the fastest and most reliable option for most people.
How to set up Time Machine (macOS Ventura and newer)
- Plug in the external drive.
- Open System Settings > General > Time Machine.
- Click Add Backup Disk and choose your drive.
- When asked, choose Erase if the drive is new or empty — Time Machine formats it as APFS for backups.
- Turn on Encrypt Backup and set a password you will remember. An unencrypted backup drive is a copy of your entire digital life that anyone can read.
- That is it. The first backup starts automatically; leave the Mac plugged in and awake until the menu-bar Time Machine icon stops animating.
On macOS Monterey and older
The steps are the same, just in a different place: System Preferences > Time Machine > Select Backup Disk, then tick Back Up Automatically.
How Time Machine keeps versions
Time Machine keeps hourly backups for the past 24 hours, daily backups for the past month, and weekly backups until the drive fills up — then it quietly deletes the oldest ones. That version history is the real value: it does not just protect you from a dead Mac, it protects you from yourself. Overwrote the wrong file on Tuesday? Wednesday's you can go get Monday's copy.
Restoring files
A single file or folder
- Open the folder where the file used to live.
- Click the Time Machine icon in the menu bar and choose Browse Time Machine Backups.
- Use the timeline on the right to step back to a date when the file existed.
- Select it and click Restore.
Everything, onto a new or repaired Mac
When a new Mac starts up for the first time (or after you reinstall macOS), Migration Assistant offers to restore from a Time Machine backup. Plug in the backup drive, pick the latest backup, and it brings back your apps, accounts, files, and settings — usually within an hour or two. We cover the whole move in our guide to moving data from an old Mac to a new one.
The backup you must make before selling or trading in
Before a Mac leaves your hands, two things need to happen in this order: back up, then wipe. Run one final Time Machine backup, confirm it finished (the menu-bar icon shows the last backup time), and only then erase the machine — our step-by-step on how to wipe a MacBook before selling it covers signing out of iCloud and Find My so the buyer does not hit Activation Lock.
If the Mac you are retiring is cracked, water-damaged, or will not boot, it still has value — see what it is worth on our broken MacBook trade-in page. And if the backup is the first step toward an upgrade, the Apple clearance collection is where the best refurbished deals land — restore your Time Machine backup onto the replacement with Migration Assistant and you pick up exactly where you left off.
Time Machine vs. iCloud — do you need both?
They solve different problems. iCloud syncs your Desktop, Documents, and Photos across devices — but if you delete a file, the deletion syncs too. Time Machine keeps historical versions on a drive you own. The safe answer is both: iCloud for convenience, Time Machine for the copy that nothing on the internet can touch.
FAQ
Can I use one drive for Time Machine and regular files?
Yes — on Ventura and newer, Time Machine uses its own APFS volume, so you can add a second volume in Disk Utility for general storage. A dedicated drive is still simpler and safer.
How often should the drive be plugged in?
Laptops: plug it in at least once a week; Time Machine catches up automatically and macOS will nag you if it has been too long. Desktops: just leave it connected.
My backup drive is full — now what?
Time Machine automatically deletes the oldest backups to make room. If it is constantly full and only holding a few weeks of history, it is time for a bigger drive.
Does Time Machine back up macOS itself?
On modern macOS it backs up your data, apps, and settings; the operating system is reinstalled separately (over the internet) and then Migration Assistant layers your backup on top.
Will a Time Machine backup from an Intel Mac restore to an Apple Silicon Mac?
Yes. Migration Assistant handles the transition — your files, accounts, and most apps come across cleanly, and Intel-only apps are flagged so you can update them.