ThirdCopy vs. Time Machine

ThirdCopy vs. Time Machine: do you need both?

Time Machine is free, built into every Mac, and backs up your whole system with deep version history. ThirdCopy is a $19.99 one-time app that keeps a folder or two mirrored to a NAS or drive, plainly and continuously. They're not really chasing the same job — here's the honest difference.

Updated August 9, 2026. Time Machine's NAS and network-protocol support has shifted more than once this year — always confirm current behavior on Apple's support site before relying on it.

Quick verdict

Time Machine and ThirdCopy solve different problems, and the honest answer for most Mac owners is to run both. Time Machine gives your whole Mac point-in-time version history you can restore from — that's not something ThirdCopy does, by design. ThirdCopy gives you a plain, current, browsable mirror of the specific folders you care about most, on a NAS or drive, without any of Time Machine's SMB/AFP protocol requirements. If you only want one: whole-system disaster recovery favors Time Machine; a simple, portable, always-current copy of your Documents or Photos favors ThirdCopy. For the details on Time Machine's NAS quirks specifically, see our guide to Time Machine and NAS backup.

	ThirdCopy	Time Machine
Price	$19.99 once	Free, built into macOS
Free trial	14 days, full-featured	Not applicable — free from day one
What it backs up	Folders you choose (Documents, Desktop, Pictures, etc.)	Your whole Mac, or selected volumes
Backup type	One-way mirror — current state only	Versioned — full history of past states
Restore method	Open the destination in Finder — plain files	Time Machine's own restore interface, or Migration Assistant
NAS / SMB destinations	Any SMB share	Only NAS models with "Time Machine over SMB" support
Legacy AFP protocol	Not applicable — SMB only	Deprecated; removed entirely in macOS 27
Continuous backup	Default — FSEvents watcher, changes caught in seconds	Hourly automatic snapshots
Destination format	Plain folders and files	Sparse bundle disk image (network destinations)
Setup	3 steps: folders, destination, schedule	One toggle; NAS setup depends on the NAS's own feature

What Time Machine actually is

Time Machine is the backup system Apple has built into every Mac since 2007. Turn it on, point it at a drive or a Time Machine-compatible NAS share, and it keeps hourly, daily, and weekly snapshots of essentially your whole system, browsable through its own restore interface. It isn't something you configure folder by folder — it's designed to protect everything, with almost no decisions to make.

Where Time Machine wins

It's free. No purchase, no trial countdown — it ships with macOS and works once you point it at a drive.
Real version history. Time Machine keeps hourly, daily, and weekly snapshots going back as far as your backup drive has room for, so you can recover a file the way it looked weeks or months ago. ThirdCopy, as a mirror, only ever shows the current state.
Whole-system coverage. It backs up your entire Mac, not just the folders you remembered to select — apps, settings, and anything else you'd otherwise forget to include.
Migration Assistant compatible. A Time Machine backup can restore a new Mac to exactly where the old one left off — genuine disaster-recovery capability ThirdCopy doesn't attempt.
Zero setup decisions. One toggle, one drive, done. There's no folder list, destination path, or schedule to think about.

Where ThirdCopy is different

A plain, browsable copy. ThirdCopy's destination is just files in folders — open it in Finder, no restore wizard, no proprietary container to fail or outgrow.
You choose exactly what's mirrored. Point it at Documents, or a shared Photos library, or a project folder — not your whole boot volume — and it stays a clean, current copy of just that.
No AFP/SMB feature to depend on. ThirdCopy writes to whatever SMB share or drive Finder can already mount. It doesn't need your NAS to ship a specific "Time Machine over SMB" feature, and it has nothing to lose when Apple retires a protocol.
Continuous by default. An FSEvents watcher catches changes and mirrors them within seconds to a couple of minutes, rather than on Time Machine's hourly cadence.
Self-healing. A second watcher on the destination itself repairs tampering or damage automatically, backed by a periodic integrity check — useful precisely because NAS backups are the ones most exposed to protocol and connectivity hiccups.

Time Machine's NAS support has had a rough 2026

If you back up to a NAS with Time Machine, 2026 is a good year to pay attention. macOS Tahoe 26.4 tightened default SMB signing behavior — plus a separate credential-handling bug — and it was widely reported across multiple independent outlets that the combination broke Time Machine backups to Synology, QNAP, UGREEN, and TrueNAS devices, with errors like "the disk image was ejected" (BACKUP_FAILED_DISCONNECTED_DISK_IMAGE). The workaround that circulated involved manually editing /etc/nsmb.conf in Terminal — not exactly a beginner-friendly fix. It's widely reported as resolved in macOS 26.5, so treat this as a documented rough patch rather than an open crisis, but it's a useful data point: Time Machine's NAS path runs through protocol details — SMB signing, AFP deprecation — that most people never think about until a backup silently stops working.

Separately, and much longer-standing, Time Machine backups to a network share have always lived inside a single growable disk image (a "sparse bundle") sitting on the share. That's a well-known corruption vector — "Time Machine must create a new backup for you" has been a familiar, unwelcome message to NAS-backup users for more than a decade, independent of anything that happened in 2026. And looking ahead, macOS 27 ("Golden Gate"), in public beta as of July 2026 with a final release expected around September 2026, removes the AFP client from macOS entirely — ending Time Machine support for older AFP-only devices like Time Capsule and the AirPort Extreme, which never spoke the newer SMBv2/v3 protocols Time Machine now requires.

None of this makes Time Machine a bad choice — a current-model NAS with up-to-date firmware is the supported, working path. But it does mean Time Machine's NAS story has more moving parts than people assume, and it's worth knowing before you're troubleshooting a failed overnight backup. See our full breakdown of Time Machine and NAS backup for the details.

Running two backup tools isn't overkill

It's tempting to treat backup software as a single choice — pick the best one and be done. But version history and a portable mirror protect against different failure modes, and neither substitutes for the other. If a drive dies, Time Machine's history doesn't help if the Time Machine drive was the one that died — a separate, current mirror on a NAS covers that gap. If a file gets quietly corrupted and you don't notice for weeks, ThirdCopy's mirror has already propagated the corruption — Time Machine's history is what saves you there. Running Time Machine locally and ThirdCopy to a NAS, or some other combination, gets you closer to a real 3-2-1 backup setup — multiple copies, on different media, with genuinely different failure modes — than leaning on either tool alone. See our 3-2-1 backup guide for Mac users for how the pieces fit together.

Questions

Does Time Machine still work with a NAS?

Yes, but only if your NAS explicitly supports "Time Machine over SMB" — Synology, QNAP, UGREEN, and TrueNAS all ship this. The older AFP protocol is already deprecated, and macOS 27 removes AFP from macOS entirely, ending support for AFP-only gear like Time Capsule and the AirPort Extreme. 2026 has also seen widely reported SMB-signing issues in macOS Tahoe 26.4 breaking some NAS backups, reportedly fixed in 26.5 — a sign Time Machine's NAS path is less bulletproof than people assume.

Should I use Time Machine and ThirdCopy together?

For most people, yes. Time Machine gives your whole Mac point-in-time version history, which ThirdCopy doesn't attempt. ThirdCopy gives you a plain, current, Finder-browsable mirror of the specific folders you care about most, without Time Machine's SMB or AFP protocol requirements. Running both gets you closer to real 3-2-1 backup — different tools, different failure modes — than relying on either one alone.

Is ThirdCopy a replacement for Time Machine?

No, and it isn't trying to be. Time Machine is a versioned system-recovery tool — it can restore your whole Mac, or an earlier version of a file from months ago, through its own restore interface. ThirdCopy only ever shows the current state of the folders you chose to mirror, with no history and no whole-Mac restore. If you need version history, keep Time Machine running.

Why did my Time Machine NAS backup say it needs to start over?

That's a long-standing issue separate from 2026's SMB troubles: Time Machine backups to a network share are stored inside a single growable disk image (a "sparse bundle") sitting on the share, and that container can corrupt. The message "Time Machine must create a new backup for you" has been familiar to NAS-backup users for more than a decade. ThirdCopy's backup destination is a plain folder of real files, not a disk image, so there's no equivalent single point of failure.

Try ThirdCopy free for 14 days — no card required.

Then $19.99 once. No subscription.

Time Machine, macOS, and Migration Assistant are trademarks of Apple Inc. ThirdCopy is made by Embay, LLC and is not affiliated with or endorsed by Apple. Figures and behavior above reflect our research as of the "Updated" date; see Apple's support site for current details.