The short answer: macOS doesn't let you password-protect a single folder in Finder. The built-in workaround is an encrypted disk image: in Disk Utility choose File → New Image → Image from Folder, pick an encryption option and a password, and work inside the mounted image. FileVault encrypts the whole disk, which protects a Mac that's off, not one folder while you're signed in. To lock the folder itself, keeping its name and path, right-click it and choose Services → Protect with ZapLock, then open it with your ZapQR sign-in and Touch ID.
Three built-in ways, and where they stop
Encrypted disk image
Disk Utility turns a folder into an encrypted .dmg that opens with a password.
- You work inside the mounted image, not the original folder
- Read-only unless you pick a writable format
- Forget the password and the image won't open
FileVault
Encrypts the entire startup disk. Strong protection if the Mac is lost while it's off.
- Once you're signed in, every folder is open
- Doesn't protect a folder on a shared or unlocked Mac
- Nothing to share per folder
Lock a note
Notes can lock individual notes with your Mac password or Touch ID.
- Works for text and attachments in Notes
- Doesn't cover Finder folders or files
- Not a folder lock
Right-click a folder, lock it where it is
ZapLock adds a Services command to Finder. The folder keeps its name and path, so aliases, Recents, Time Machine and sync clients keep pointing at it.
Open it in ZapLock to browse files, or choose Unlock in place to turn it back into a normal folder for every app until you lock it again.
Illustration · labels can vary by version
How to lock a folder on a Mac with ZapLock
Needs macOS 14 or later.
Install ZapLock
Get it from the Mac App Store and sign in with a free ZapQR account.
Sign in on a second device
Sign in on your iPhone or another computer too. Then losing one device doesn't lock you out of your folders.
Lock the folder
In Finder, right-click the folder and choose Services → Protect with ZapLock. Or click the ZapLock icon in the menu bar, or use the app window. If Services doesn't list ZapLock, open the app once.
Turn on Touch ID
In Settings → Unlock check, require Touch ID before any folder opens on this Mac. A copied sign-in alone then opens nothing.
Open it when you need it
Browse it inside ZapLock, or choose Unlock in place to use it with any app. It locks again when the Mac sleeps, when its screen locks, when you quit ZapLock, or after the idle time you set.
Prefer the built-in way? Make an encrypted disk image
Open Disk Utility
It's in Applications → Utilities.
Choose File → New Image → Image from Folder
Pick the folder, name the image and choose where to save it.
Pick encryption and a format
Choose an option from the Encryption menu and set a password. For an image you can keep adding files to, choose a writable format rather than read-only.
Delete the original
The image is a copy. Once you've checked it opens, delete the original folder and empty the Trash, or the plain files are still on your Mac.
What ZapLock won't do
Worth knowing up front, so nothing surprises you later.
- You need a free ZapQR account. That sign-in is what replaces the password.
- Opening a folder needs a connection to our service, which releases its half of the key. A new unlock waits until you're back online.
- If a folder's key lives on only one device and you lose that device, the folder can't be opened. Sign in on a second device before you lock anything you can't lose.
- No Linux, and the apps aren't open source.
- Sync services keep version history. If plain copies were ever synced, your provider may still hold them.
Mac folder lock FAQ
Can I password-protect a folder on a Mac without an app?
Not the folder itself. The built-in way is to make an encrypted disk image of it: in Disk Utility choose File → New Image → Image from Folder, pick an encryption option and set a password. You then open the image, not the folder, and the original stays unencrypted until you delete it.
Does FileVault lock individual folders?
No. FileVault encrypts the whole startup disk, which protects your Mac if it's lost or stolen while it's off. Once you're signed in, every folder is readable by anyone at the keyboard and by every app you run.
How do I lock a folder on a Mac with Touch ID?
Install ZapLock, lock the folder, then turn on Settings → Unlock check. Every folder then asks for Touch ID, falling back to your Mac password, before it opens on that Mac. The check is free on every plan.
Is there a free folder lock for Mac?
Yes. ZapLock's Free plan locks one folder for good, and opening folders is always free. Disk Utility's encrypted images are free too. Personal is $49 a year on the web for unlimited folders. See pricing.
Will a locked folder still back up and sync?
Yes. ZapLock keeps the folder's name and path, so Time Machine, iCloud Drive, Dropbox and Google Drive keep backing it up and syncing it, but they only see encrypted files. Sync services keep version history, so clear old plain copies with your provider if it matters to you.
Can I open a folder I locked on my Mac from my iPhone or a Windows PC?
Yes. Every ZapLock app uses the same folder format. Keep the folder somewhere both devices reach, like iCloud Drive or Dropbox, add it on the other device, and your Mac hands that device its key the first time. See locking folders on iPhone.
Lock your first folder in a minute.
Free for one folder, for good. On Mac, Windows, iPhone, iPad and Android.
Built-in options checked 22 October 2026 against: Apple: Create a disk image with Disk Utility.