How do you sync two folders on a Mac?

By Kayabyte · Last updated 13 November 2026

Short answer: Finder can copy one folder over another, but it does not sync: it does not compare dates, does not delete anything for you and never tells you what changed. For a one-off copy that is fine. For folders that must stay the same, use rsync in Terminal (free, built in, no preview unless you ask for a dry run) or an app. Pairfold is a Mac app that keeps two folders in step, shows every change before it makes it, and moves replaced or removed files to an archive folder instead of deleting them. It needs macOS 26 or later; the app page has the current price and where to get it.

Method 1: Finder

Drag the folder to the other location while holding Option. If a folder with the same name is already there, Finder offers Stop, Replace, or, with Option held, Merge. Merge keeps files that exist only in the destination and replaces files that have the same name. In our reading it does not ask which of the two files is newer, so check before you merge over work you care about.

What it cannot do: remove files you deleted in the source, copy only what changed, run on its own, or sync back the other way.

Method 2: rsync in Terminal

macOS includes rsync. On the Mac we checked (macOS 27) /usr/bin/rsync is openrsync, a rewrite that says it is “rsync version 2.6.9 compatible”, so some options of the newer rsync you may see in tutorials are missing. A safe first command is a dry run:

rsync -avn ~/Projects/ /Volumes/Backup/Projects/

-a keeps dates and permissions, -v lists files, -n changes nothing. Drop the n to copy. The trailing slash on the source matters: with it you copy the contents, without it you copy the folder itself into the destination. Add --delete to make the destination an exact mirror, and see rsync on Mac explained before you do, because it deletes for real.

rsync copies one way. For two-way sync you would run it twice with -u (skip files that are newer on the destination), which cannot notice deletions and can overwrite a file you edited on both sides.

Method 3: Automator, Shortcuts or a Folder Action

These can run a shell script or copy files when something happens. They run the same copy as above, without a preview, and we would not rely on them for anything you cannot afford to lose.

What a sync app adds

A list of what will change before it changes.
Mirror (the second folder follows the first) or two-way.
A record of what the last sync did.
Runs by schedule, or when a drive is connected.

With Pairfold

Pairfold keeps pairs of folders. In Mirror mode the second folder becomes a copy of the first and the first is never changed. In Two-way mode new and changed files go both ways, a deletion is noticed because Pairfold remembers the state after the last sync, and when both sides changed the same file it leaves the file for you to decide. Every file is copied under a temporary name, checked, and then put in place. Replaced and removed files go to a dated archive folder.

Limits: pairs of folders only (no FTP, SFTP or cloud services by itself), macOS 26 or later, and scheduled runs need Pairfold open in the menu bar.

Steps with Pairfold

Open Pairfold and click New Pair. Choose the first and the second folder.
Choose Mirror or Two-way.
Click Check and Preview and read the list: New, Changed, To archive, Conflicts.
Untick anything you want left alone, then click Sync.

Get Pairfold: see the app page for where to get it

Questions

Does Finder sync folders? No. Finder copies and can merge, but it does not compare dates, remove deleted files or run on its own.

Is rsync safe for syncing folders? Without --delete it only adds and replaces. With --delete it removes files from the destination. Always run it once with -n first.

What is the difference between sync and backup? A sync makes two places match, so a mistake can reach both. A backup keeps older versions. Pairfold’s archive keeps the files it replaces or removes, which gives you some history, but it is not Time Machine. See Time Machine vs folder sync.

Does Pairfold delete files? No file is deleted outright. The old version goes to the archive folder.

Apple, Mac, macOS, Finder, Time Machine, and iCloud are trademarks of Apple Inc. Pairfold is made by Kayabyte and is not affiliated with or endorsed by Apple.