How to Lock a Folder on Mac: Three Different Meanings

Steps use macOS 14 and later names. Menu wording can differ slightly between versions.

Which kind of lock do you need?

Option 1: the Locked checkbox (stops changes)

1. Select the folder in Finder

   Click it once.

2. Open Get Info

   Press ⌘I. Apple lists this shortcut as the one that shows the Get Info window for the selected item.

3. Tick Locked

   It is in the General section. The folder can no longer be renamed, moved to the Trash or changed. Apple's help page describes this checkbox for documents, so test it on your folder before you rely on it.

That flag applies to the folder itself. Files inside can still be edited. To lock everything inside as well, use Terminal:

chflags -R uchg ~/Documents/Taxes
chflags -R nouchg ~/Documents/Taxes

What the Locked checkbox does not stop

• Reading. Apple describes the lock as protection from accidental change or deletion. It says nothing about keeping anyone out.
• The Trash. Apple says that if you move a locked document to the Trash you get a warning, and that emptying the Trash deletes it. The lock slows deletion down. It does not prevent it.
• Changes to the files inside a folder. Each file has its own flag. Use the Terminal command above to set it on all of them.

Option 2: permissions (keeps other accounts out)

1. Open Get Info

   Select the folder and press ⌘I.

2. Expand Sharing & Permissions

   Click the arrow if the section is closed, then click the padlock at the bottom right and authenticate. If the settings are greyed out, the padlock is still closed. Apple's wording is "Click the lock to unlock permission settings."

3. Change access

   Set "everyone" to No Access. Leave your own account on Read & Write. Apple lists four settings: Read & Write, Read only, Write only (Drop Box) and No Access.

4. Apply it to the contents

   Click the Action pop-up menu at the bottom of the window and choose Apply to enclosed items. Apple describes this as the way to pass the setting to everything inside the folder.

5. Undo a mistake

   Before you close the Info window, choose Revert changes from the same Action menu.

chmod -R go-rwx ~/Documents/Taxes

This helps when several people each have their own account on the Mac. It does nothing if someone is logged in as you, and an administrator can change permissions back. Create separate accounts in System Settings > Users & Groups for each person.

Account type matters. Apple says a Standard user can install apps and change their own settings but cannot add users or change other users' settings. An administrator can add and manage other users. Give family members or coworkers Standard accounts where you can. Apple does not say what one account may read in another account's folders by default, so do not assume. Run the permissions test below. The shared family Mac scenario walks through a typical setup.

Option 3: encryption (hides the contents)

To keep files unreadable even when someone is at your unlocked Mac, put them in an encrypted container. The full steps are in how to password protect a folder on Mac. Without Disk Utility, see the Terminal and app routes. For more on the container itself, read encrypted disk images on Mac.

Two Apple warnings apply to every encrypted image. If you forget the password, you cannot open the image or read its files. While the image is mounted, anyone with access to your computer can use the files in it. Eject it when you finish.

Test that your lock works

1. Locked checkbox: try to rename the folder and drag it to the Trash. You should see a refusal or a warning. Reading it should still work, which is the expected result.
2. Permissions: an administrator can create a Standard test account in System Settings > Users & Groups. Log in as that user and try to open the folder. Delete the test account afterwards.
3. Encryption: eject the image, then try to open a file from Finder. It must not open. Mount the image again with the password and check that every file is there before you delete any original.
4. Screen lock: press ⌃⌘Q, wake the display and check that it asks for your password.

What a lock leaves behind

A lock stops a person. It does not stop the Mac from keeping its own records. Check these four places.

• Time Machine. A backup made before you encrypted still holds the plain files. Apple says excluded items still appear in Time Machine local snapshots, so exclusion is not a clean erase. The Options button is in System Settings > General > Time Machine.
• Spotlight. Search may show names of files it has indexed. To keep a folder or disk out of search, add it in System Settings > Spotlight > Search Privacy. Apple warns that this can stop update notices for some apps.
• Recent items. Apple menu > Recent Items lists documents you opened lately. Choose Clear Menu to empty it.
• Go to Folder. Apple says Go to Folder offers recent pathnames as you type, so a path you used before can reappear.

If you mean lock your whole Mac

• Press ⌃⌘Q to lock the screen right now. Apple lists it as the shortcut that locks your screen.
• In System Settings > Lock Screen, set the password requirement after the screen saver or display sleep to Immediately. Apple names the setting "Require password after screen saver begins or display is turned off".
• Turn on FileVault in System Settings > Privacy & Security so a stolen Mac cannot be read.

Apple notes that locking the screen does not stop other users from turning off the Mac, restarting it or logging in. FileVault needs your login password. If you lose both the password and the recovery key, Apple says your files and settings are lost forever. Read what FileVault is before you turn it on.

Where Hidden Folder fits