Free · macOS 15+ · Menu bar app

Sync Mac folders to external SSDs, automatically.

Plug in the drive. Your folders follow.

SSDSync copies your folders to external SSDs the moment they're connected, or on a schedule. It adds new files and updates changed ones, and never deletes anything on the destination.

Download on the Mac App Store Free on the Italian Mac App Store · macOS 15+

Illustration of a laptop connected to two portable SSDs by blue cables, with paper files travelling along the cables

Trigger: On connectRuns when every drive a job needs is mounted.
Mode: Add & updateNew and changed files only. No deletions, ever.
Identity: Volume UUIDRenamed or duplicate drive names can't fool it.
Schedule: 15 min → weeklyOptional timer that survives restarts.

01 — How it works

Mac to SSD. SSD to SSD. Set it once.

A job is a source, a destination and the drives that must be connected. Create as many as you like: back up a Mac folder to your archive SSD, then copy that archive onto a second drive whenever both are plugged in. Each job copies in one direction.

Pick a source and a destination
A folder on your Mac or on any external drive, chosen with the standard macOS folder picker.
Choose the trigger drives
One drive, or several that must all be connected. Plugging in a hub with both? The job still runs once, not twice.
Just plug in
SSDSync waits in the menu bar, runs jobs one at a time and sends a notification with files and bytes copied.

02 — Safety model

Adds and updates. Never deletes.

In mirror mode, a sync propagates deletions: delete something by mistake on your Mac and the copy disappears too. SSDSync has a single mode, and it isn't that one. New files are copied, changed files are updated, and anything that lives only on the destination stays exactly where it is.

Updating a file replaces the older copy at the destination. SSDSync keeps copies, not a version history: for that, keep Time Machine too.

There is no --delete option to switch on by accident. SSDSync also refuses jobs whose destination is the source itself or a folder inside it.

Source · ~/Photos

2026/Italy/IMG_2841.HEICnew
2026/Italy/edit-final.psdchanged
2025/Summer/beach.movunchanged

SSD Archive · after sync

2026/Italy/IMG_2841.HEICcopied
2026/Italy/edit-final.psdupdated
2025/Summer/beach.movuntouched
2019/Old-wedding-album/kept

03 — The app

Everything in one window, nothing in the way.

Lives in the menu bar. Open the main window when you want to see what ran, what's next and why.

SSDSync main window showing a job that copies a Mac photo folder to an SSD, with its paths, automation and last successful run — **Fig. 1**Each job shows its paths, trigger drives, next scheduled run and last result.

A job that copies one SSD to another, waiting for both drives to be connected — **Fig. 2**Drive-to-drive jobs wait for both disks.

Job editor with automation toggle, schedule interval, source folder and destination volume — **Fig. 3**The job editor: trigger, schedule, source, destination.

Log window listing a sync run with files transferred, data size, duration and destination-only files preserved — **Fig. 4**A readable log for every run, kept for 30 days, without opening Finder.

04 — Details

Small app, careful defaults.

Automation

Runs on connect

Mount events are debounced, so a hub full of drives triggers each job once.

Schedule

Every 15 minutes to weekly

A due job waits until its drives are back, then runs.

Queue

One job at a time

Runs never overlap, and stale locks from a crash can be cleared in one click.

Notifications

Start and finish

The completion notice tells you the outcome, files and bytes copied.

Exclusions

No .DS_Store clutter

System files are skipped by default; add your own patterns per job.

Starts with your Mac

One toggle, and SSDSync is in the menu bar after every restart.

Unplug

Handles a pulled drive

Disconnect a drive mid-run and the copy stops, is logged and notified. The next run completes it.

Engine

Built-in openrsync

Proven rsync transfers bundled in the app, sandboxed as the Mac App Store requires.

Privacy

Nothing leaves your Mac

No account, no analytics, no network. Your config and logs stay local.

05 — Questions

Before you plug in.

Can SSDSync delete files on my drive?

No. SSDSync copies new files and updates changed ones. Files that exist only in the destination are always left in place, and the app never runs rsync with a delete option. Updating a file replaces the older copy at the destination: SSDSync keeps copies, not a version history.

Is SSDSync a Time Machine replacement?

No. Time Machine keeps versioned snapshots of your whole Mac. SSDSync keeps plain copies of the folders you choose on the drives you choose: ordinary files and folders you can browse in Finder, with no restore step. You can use it alongside Time Machine.

What happens if I unplug a drive during a sync?

SSDSync notices the unmount, stops the running copy, records the interruption in the log and notifies you. Files already copied stay on the drive; the next time the job runs, it copies whatever is still missing or changed.

Where can I get SSDSync?

SSDSync is free on the Mac App Store, where it is currently listed on the Italian storefront, and requires macOS 15 or later on Apple silicon or Intel.

Does SSDSync collect any data?

No. There is no account, no analytics and no network code. Configuration and logs stay in your Library folder.

Your next copy is one cable away.

Free on the Italian Mac App Store, for macOS 15 or later. Set up a job in a minute and forget about it.

Download on the Mac App Store

SSDSync is free and made by one developer. If it has saved your files, or your evenings:

Buy me a coffee