The fastest real backup for a Mac is Time Machine plus an external drive: plug in a drive, turn Time Machine on, and macOS handles the rest automatically. That covers your whole Mac, including a full system restore if the internal drive ever fails. It has two real gaps though: it doesn't reach files that live on other external drives, and it's not offsite, so a fire, theft, or a drive failure that takes out both copies at once still loses everything. This guide covers the full setup: Time Machine itself, what changes for a laptop that isn't always at a desk, backing up without Time Machine if you'd rather copy files manually, adding a cloud layer, and how to actually confirm a backup worked instead of assuming it did.
TL;DR: Time Machine to an external drive covers your whole Mac automatically. Add a cloud backup (Backblaze or similar) for the offsite copy, since a drive next to your Mac doesn't protect against fire or theft. Neither one backs up files on your other external drives, which needs a separate tool if that's where your projects live.
How Do You Back Up a Mac?
Turn on Time Machine with an external drive connected, and macOS backs up your entire internal drive automatically from that point on: system files, apps, documents, photos, everything, with hourly snapshots you can restore from later. That's the built-in answer and it's genuinely good for what it covers. The two things worth adding on top are a cloud backup for offsite protection, and a plan for anything that lives outside your Mac's internal drive, since Time Machine ignores external drives by default.
Set Up Time Machine
- Connect an external drive. It needs to be formatted as APFS or Mac OS Extended (Journaled); a drive fresh out of the box formatted for Windows (NTFS or exFAT) needs reformatting first in Disk Utility, which erases it.
- Open System Settings → General → Time Machine.
- Click Add Backup Disk, select your drive, and confirm.
- Time Machine starts its first backup immediately. The first one copies everything and can take hours depending on how much you have stored; every backup after that only copies what changed, and takes minutes.
Size the drive at roughly twice your Mac's used storage. Time Machine keeps hourly backups for the past 24 hours, daily backups for the past month, and weekly backups beyond that, which needs headroom to grow into. A Mac with 500GB used wants at least a 1TB backup drive.
How to Back Up a MacBook (It's Different From a Desktop)
A MacBook that travels changes the setup in one real way: Time Machine can only back up when the drive is connected, and a portable Mac spends a lot of time away from wherever that drive sits. Two options handle this:
A portable drive you actually carry. A small bus-powered SSD (the kind that needs no separate power cable) can travel with the MacBook and get plugged in for a few minutes when you're at a desk. This is the simplest fix and works with the exact Time Machine setup above.
A NAS as a network Time Machine destination. A Synology or QNAP box (or Time Machine over SMB to any capable network drive) lets the MacBook back up automatically over Wi-Fi whenever it's on the same network, no cable required. Setup takes longer than a direct drive but removes the "remember to plug it in" problem entirely. The NAS backup workflow guide covers this in detail.
Either way, closing the lid mid-backup doesn't corrupt anything. Time Machine resumes an interrupted backup from where it left off next time the drive is available.
How to Back Up a Mac to an External Drive Without Time Machine
Some people want a manual copy instead of continuous snapshots, usually because they want full control over what gets copied and when. Two ways to do that:
Drag and drop in Finder. Copy the folders you care about to the external drive directly. It works, but Finder gives you no verification that the copy is byte-for-byte identical to the original, and no easy way to update only what changed on a second pass without re-copying everything.
rsync in Terminal, which solves both of those problems:
rsync -av --progress ~/Documents/ /Volumes/BackupDrive/Documents/
-a preserves file permissions and timestamps, -v shows what's copying, and running the same command again only copies files that changed or are new, rather than re-copying everything. It's free, reliable, and has been the standard Unix tool for this for decades. The tradeoff is that it's a manual step you have to remember to run; nothing about it happens automatically the way Time Machine does.
Actually Verify the Backup Worked
The step almost every guide skips: check that the backup is real before you trust it. For Time Machine, open Time Machine from the menu bar and browse into the backup to confirm your files are actually there and readable, not just that a backup icon shows a checkmark. For a manual copy, compare folder sizes between the original and the copy (right-click each in Finder and choose Get Info) as a basic sanity check that everything transferred.
Neither of those catches silent corruption in an individual file, the kind where a copy technically finished but a handful of bytes got dropped. That takes checksum verification, which we cover in the section on project files below, since it matters most for large media files that are expensive to reshoot or re-render if a copy turns out to be bad.
Add a Cloud Backup for Offsite Protection
An external drive sitting next to your Mac protects against drive failure. It does nothing if your house floods, the drive is stolen along with the Mac, or anything else destroys both at once. This is the idea behind the 3-2-1 rule: keep 3 copies of anything that matters, on 2 different types of storage, with 1 of those copies offsite. In practice: the original on your Mac, a backup on an external drive, and a third copy in the cloud.
Backblaze Personal Backup is the simplest way to add that third copy: install it, point it at your Mac, and it uploads continuously in the background for a flat $99/year with no storage cap. For project files on external drives that need the same offsite protection, S3-compatible storage (Backblaze B2, Wasabi, Cloudflare R2) works out cheaper per terabyte at scale; the cloud storage cost calculator runs the numbers against how much you actually store.
What Time Machine Doesn't Cover
Time Machine backs up your Mac's internal drive. It does not back up external drives unless you manually add them as a source, and even then, you're back to a single destination with no way to check whether a specific file is actually confirmed safe before you delete anything.
That gap matters most if your real files (video projects, photo libraries, client work) live on external drives rather than your internal disk, which is common once a project folder gets into the hundreds of gigabytes. For that specific situation:
Tusk is a Mac app that automatically backs up your project folders to multiple locations and tracks where every file lives — even when your drives aren't connected.
Tusk backs up project folders to external drives and cloud storage at the same time, verifying every file with a BLAKE3 checksum as it copies, so a bad transfer gets caught immediately instead of three months later when you try to restore. It tracks exactly which drive holds a verified copy of any given file, even when that drive is unplugged and sitting on a shelf, and it won't let you delete a local copy until every backup destination has confirmed it. None of that replaces Time Machine for your Mac's system and internal files; it covers the part Time Machine was never built for.
FAQ
Connect an external drive formatted as APFS or Mac OS Extended, then go to System Settings → General → Time Machine, click Add Backup Disk, and select the drive. Time Machine backs up your entire internal drive automatically from that point on, with the first backup taking longer than later ones since it copies everything once.
The same Time Machine setup works, with one adjustment: since a MacBook travels, either use a small portable SSD you can plug in periodically, or set up a NAS as a network Time Machine destination so backups happen automatically over Wi-Fi without a cable. A direct drive connection is faster; a NAS removes the need to remember to plug anything in.
Copy files manually in Finder by dragging them to the drive, or use rsync in Terminal (rsync -av --progress ~/Documents/ /Volumes/BackupDrive/Documents/) for a repeatable copy that only transfers what changed on later runs. Finder gives no verification the copy is intact; rsync is more reliable but requires running it yourself rather than backing up automatically.
It backs up your entire internal drive by default: system files, apps, documents, photos, and any folder on that drive. It does not back up external drives unless you add them manually as a source, and it has no offsite component, so a local disaster (fire, theft) can take out the Mac and the Time Machine drive together.
With Time Machine running, this isn't a manual decision: it backs up hourly as long as the drive is connected. If you're backing up manually instead, daily is reasonable for active work, but the bigger risk with manual backups is usually forgetting to run them at all, which is the main advantage automatic tools have over a remembered routine.
For most people's internal-drive files, yes, as long as the backup drive is reasonably reliable. It's not enough on its own if you also store files on external drives (which Time Machine ignores by default), or if you need protection against a local disaster that could destroy both the Mac and the backup drive together, which is what a cloud backup or offsite copy is for.