ThirdCopy
Backups that just happen
Only for Mac
Free · In‑App Purchases
Mac
Your Mac is copy one. iCloud is copy two. ThirdCopy is the third copy — the one you never have to think about.
ThirdCopy is a small, focused menu bar app that keeps an exact, one-way mirror of the folders you care about on your NAS, network share, or external drive. No sync jargon, no tasks to configure, no manual to read.
SET UP IN A MINUTE
One click adds your whole user folder (Desktop, Documents, Pictures, and everything else you keep there), or pick specific folders yourself. Pick where the backup lives, done.
BACKS UP AS YOU WORK
ThirdCopy watches your folders and mirrors changes within seconds of them happening. Prefer a schedule? Hourly, daily, weekly, or manual — your call.
ONE DIRECTION. NO SURPRISES.
Mirror backup means the backup always matches the source, exactly. Files you add are copied, files you change are updated, and files you delete are removed — or kept for a while with the optional deleted-files safety net. There is never a risk of a stale backup overwriting your real files.
HEALS ITSELF
If files at the backup are deleted or damaged, ThirdCopy notices and repairs them. A periodic health check keeps the backup verified even when nothing changed.
WORKS WITH iCLOUD
Files that are “on demand” in iCloud are downloaded just long enough to back up, then returned to the cloud — your disk space stays free.
SKIPS WHAT DOESN'T NEED BACKING UP
Common developer folders like node_modules are excluded automatically, so your backup stays focused on what you actually made. Exclude anything else by name too: build output, dependencies, whatever you don't need duplicated.
ALWAYS HONEST
The menu bar icon shows your backup’s state at a glance, with live progress while it runs. Every run records exactly what changed — and when a backup can’t run, ThirdCopy tells you why in plain language: drive not connected, disk full, no permission. Never a silent skip.
BUILT FOR TRUST
• One-way mirror only — no bidirectional sync ambiguity
• Deletions are safety-gated: ThirdCopy will never wipe a folder it doesn’t own
• An empty or unreadable source can never empty a healthy backup
• Sandboxed, no accounts — your files never leave your Mac except to the destination you choose
ThirdCopy backs up to any local drive, external disk, or mounted network share (SMB/AFP) — Synology, QNAP, UGREEN, TrueNAS, or a plain shared folder on another machine.
Questions? support@thirdcopy.app
- This app hasn’t received enough ratings or reviews to display an overview.
Faster, simpler setup, plus a couple of fixes:
- One click now adds your whole user folder as a single backup source, with Library and hidden system files (like SSH keys) skipped automatically.
- Common developer folders (node_modules, .build, and others) are excluded by default in new setups.
- Fixed the folder picker sometimes opening in the wrong location.
- Fixed the menu bar icon getting stuck on an old percentage after resetting backup setup.
The developer, Embay, LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Usage Data
- Diagnostics
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Embay, LLC
- Size
- 2.3 MB
- Category
- Utilities
- Compatibility
Requires macOS 14.0 or later.
- Mac
Requires macOS 14.0 or later.
- Mac
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- ThirdCopy Forever (Offer) $14.99
- ThirdCopy Forever $19.99
- Copyright
- © 2026 Embay, LLC