How to back up your Mac with Time Machine
One external drive and ten minutes of setup gives a MacBook a complete, versioned, automatic backup. Here's the whole process.
Last updated 2026-06-12 · 4 minute read · Applies to: MacBook, iMac, Mac mini
Half the MacBooks that come across our bench have no backup at all, and MacBooks fail in ways that take the data with them (liquid into the logic board, dead SSDs that are soldered to it). Time Machine is built into every Mac, it's genuinely good, and it needs exactly one thing from you: a drive to back up to.
1. Get a drive that's big enough
Any USB-C/USB-A external drive works. Rule of thumb: at least double your Mac's storage. A 256GB MacBook wants a 500GB+ drive, 512GB wants 1TB. A basic 1TB portable drive is usually around $70–$90.
2. Plug it in and accept the prompt
macOS usually asks straight away: *'Do you want to use this drive to back up with Time Machine?'* Click Use as Backup Disk. Turn on encryption when offered: if the drive is ever lost, your files stay private.
3. No prompt? Set it manually
System Settings → General → Time Machine → Add Backup Disk, pick the drive, done. macOS will offer to erase the drive if it's in the wrong format. Let it (after moving off anything you need).
4. Let the first backup finish
The first run copies everything and can take a few hours, so leave the Mac on charge overnight. After that, backups are incremental and take minutes. Hourly while the drive is connected.
5. Verify and make it a habit
Click the Time Machine icon in the menu bar to see the latest backup time. A backup drive that lives plugged in (or comes out every Friday) is the difference between an annoying repair and a devastating one.
Warning: iCloud mirrors your files, including deletions and corruption. If a file is deleted or ransomed, iCloud faithfully syncs the damage. Time Machine keeps versions going back months. You want both, but only one of them is a backup.
Frequently asked questions
Can I use one drive for two Macs?
Yes. Time Machine creates a separate backup per Mac on the same drive. Just size the drive for both machines combined.
My MacBook is dead. Is the data gone?
Not necessarily. Depending on the model and fault we can often repair the board or recover the SSD contents; see data recovery. Apple Silicon Macs make this harder, which is exactly why Time Machine matters.
What about backing up to a NAS or over the network?
Works well once set up (Time Machine supports network targets), but it's fiddlier than a USB drive. If you want a set-and-forget home setup, ask us. It's a common small job.
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