ThirdCopy vs. SuperDuper!

ThirdCopy vs. SuperDuper!: a simpler way to mirror your Mac to a NAS

SuperDuper! is Shirt Pocket's bootable-clone specialist, just rebuilt from the ground up as SuperDuper 4. Its free version runs forever but with real limits; ThirdCopy is a $19.99 one-time mirror tool built for NAS and drive backups from day one, with nothing locked during its 14-day trial.

Updated August 9, 2026. Pricing and features change — always confirm current details on Shirt Pocket's site before buying.

Quick verdict

If your priority is a bootable, disaster-recovery-grade clone of your whole Mac — the job SuperDuper is built around — its Smart Update engine and SD4's newly rewritten NAS support make it a serious, well-regarded option. If you just want a folder or two mirrored to a NAS or external drive, continuously, without hitting a paywall to turn on scheduling, ThirdCopy does that one job for less than half SD4's price, with nothing locked during its trial.

	ThirdCopy	SuperDuper!
Price	$19.99 once	SuperDuper 4: around $43.95 once (Classic, for older Macs: $27.95)
Free trial	14 days, full-featured	None — free version runs forever, but is capability-limited (see below)
Ongoing cost	None, ever	None, ever
Setup model	3 steps: folders, destination, schedule	Choose source, destination, copy method, schedule
One-way mirror backup	Yes — the only mode	Yes, via Smart Update (registered) or Erase-then-copy (free)
Bootable clone	Not offered, by design	Yes — SuperDuper's core focus (local drive only, never over a network)
Continuous backup	Default for every backup	Not offered — schedule-based only
NAS / SMB share support	Yes	Yes in SD4, first-class as of Aug 2026; registered only, never bootable
Mac App Store / sandboxed	Yes, full feature set	No — direct download, background helper process
Deleted-file handling	Optional holding period	Erase-then-copy overwrites everything; Smart Update syncs incrementally
Minimum macOS	14 Sonoma	SD4: 14 Sonoma · Classic: 13 and earlier

What SuperDuper actually is

SuperDuper! is Shirt Pocket's Mac cloning tool, best known for "Smart Update" incremental backups and bootable, disaster-recovery-grade whole-Mac clones. On August 2, 2026 — about a week before this was written — Shirt Pocket shipped SuperDuper 4, a ground-up rewrite and the first paid upgrade in the product's history; the previous codebase lives on as SuperDuper Classic for Macs on macOS 13 Ventura or earlier. Both are sold directly from shirt-pocket.com, not through the Mac App Store.

Where SuperDuper wins

SD4 is a real step forward, and SuperDuper has genuine strengths ThirdCopy doesn't try to match:

Genuinely improved NAS support in SD4. Network shares over SMB, AFP, or NFS are now first-class direct destinations — no pre-mounting, no manual sparse-bundle-image workaround that SD3 and Classic required. That's a real, recent fix to what used to be SuperDuper's weakest area.
Bootable clones as the core design. Disaster-recovery-grade whole-Mac clones, built from a local, directly-attached, erasable drive, are what SuperDuper is for — not a bonus feature bolted onto a mirror tool.
Runs forever for free. The unregistered version never expires. It's capability-limited rather than full-featured (see below), but there's no trial clock counting down.
A reputation for approachability that predates SD4 by two decades. Historically seen as the friendlier of the two major Mac clone tools, alongside a Macworld Eddy Award in both 2005 and 2006.
One-time upgrade pricing, not a subscription. Same "buy it once" model as ThirdCopy, just at a higher price point — and existing SD3 owners get a free-or-discounted path to SD4 rather than paying full price again.

Where ThirdCopy is simpler

No registration wall. ThirdCopy's 14-day trial includes scheduling and NAS destinations from the first launch. SuperDuper's free version runs forever, but Smart Update, scheduling, and network destinations are all locked until you pay and register — the free tier can only run a full, destructive "Erase, then copy" every single time.
Continuous by default. ThirdCopy watches your folders and mirrors changes automatically. SuperDuper is schedule-based; there's no watch-and-mirror mode.
Sandboxed and on the Mac App Store. ThirdCopy runs entirely in the App Sandbox. SuperDuper isn't sandboxed — it runs backups through a background helper process that keeps going even after you quit the app, which is part of why it can't be sandboxed the way an App Store app must be.
Built for NAS mirroring, not whole-Mac cloning. SuperDuper's core design goal is a bootable disaster-recovery clone, and a NAS destination in SD4 can never be bootable. ThirdCopy was built for exactly the NAS and external-drive mirror job from the start, so there's no clone-tool baggage to route around.
Lower price for the core job. If backing up a folder or two to a NAS is all you need, ThirdCopy's $19.99 gets you there without paying for, or working around, a bootable-cloning engine — SuperDuper 4 runs around $43.95 to unlock the features you'd actually be using.

The honest tradeoff

SuperDuper's reputation for being the simpler of the two big Mac clone tools is earned, and SD4's networking rewrite closes a real gap that used to send NAS-focused users elsewhere. But "simpler than Carbon Copy Cloner" and "simple" aren't the same claim: SuperDuper is still built first for bootable, whole-Mac disaster recovery, and its free tier exists mainly to let you try Erase-then-copy, not to run scheduled NAS backups without paying. ThirdCopy skips the cloning half of the job entirely and prices the rest — scheduled or continuous mirroring to a NAS or drive — at under half of SD4's cost, with no registration wall during the trial.

Questions

Is SuperDuper free?

The unregistered version runs forever for free, but it's capability-limited, not simply time-limited: it can only perform a full "Erase, then copy" backup — a complete, destructive copy every run — with Smart Update (incremental copying), scheduling, and network/NAS destinations all locked until you pay and register. SuperDuper 4 costs around $43.95 once (SuperDuper Classic, for macOS 13 and earlier, is $27.95). ThirdCopy's 14-day trial is time-limited but has no feature gate — scheduling and NAS destinations both work from the first launch.

Can SuperDuper back up to a NAS?

Yes, and as of SuperDuper 4 (shipped August 2, 2026) it's much easier than before: network shares over SMB, AFP, or NFS are now first-class destinations, with no pre-mounting and no manual sparse-bundle-image workaround required, which earlier versions and SuperDuper Classic needed. One limit carries over unchanged: a network destination can never be a bootable clone — bootable backups require a local, directly-attached, erasable drive.

Does SuperDuper back up continuously, in real time?

No. SuperDuper runs on schedules you set; it doesn't watch folders for changes and mirror automatically. ThirdCopy's continuous mode is the default for every backup — an FSEvents watcher detects changes and mirrors them shortly after, with time-based schedules available as a customization, not the default.

Is SuperDuper sandboxed or on the Mac App Store?

No. SuperDuper is downloaded directly from Shirt Pocket's website and isn't sandboxed — it runs backups through a background helper process that keeps working independently of the app, even if you quit it, which is part of why it isn't built for the App Sandbox. ThirdCopy is sandboxed and distributed only through the Mac App Store.

Try ThirdCopy free for 14 days — no card required.

Then $19.99 once. No subscription.

SuperDuper! and SuperDuper are products of Shirt Pocket, LLC. ThirdCopy is made by Embay, LLC and is not affiliated with or endorsed by Shirt Pocket. Figures above reflect our research as of the "Updated" date; see Shirt Pocket's site for current pricing.