Finder does not include a simple right-click “encrypt this folder” command. The built-in Mac method is to create an encrypted disk image: a password-protected container that opens like a temporary drive when unlocked.
This guide applies to recent macOS versions using Disk Utility. No third-party encryption app is required.
Does This Affect You?
Use an encrypted disk image for tax records, personal documents, client files, or any folder you want protected separately from the rest of the Mac.
Create an Encrypted Disk Image from a Folder
- Open Disk Utility from Spotlight or Applications > Utilities.
- Choose File > New Image > Image from Folder.
- Select the folder you want to protect and click Choose.
- Name the disk image and choose where to save it.
- Choose 128-bit AES for faster encryption or 256-bit AES for stronger protection.
- Enter and confirm a password. Leave Remember this password in my keychain unchecked if you want the password required every time.
- Choose Read/write if you want to add or remove files later, or Compressed for a smaller locked archive.
- Click Save. Disk Utility creates a .dmg file.
- After confirming the encrypted image opens correctly, delete the original unencrypted folder and empty Trash if you do not want a plain copy left behind.
- To use it later, double-click the .dmg, enter the password, use it like a drive, then eject it to lock it again.
Encryption Notes
There Is No Forgot Password Button
If you lose the disk image password and did not save it in Keychain or a password manager, the contents are effectively unrecoverable. That is the point of the encryption.
Create a Blank Container Instead
Use File > New Image > Blank Image if you want an empty encrypted container of a set size to fill over time.
Use FileVault for the Whole Mac
FileVault encrypts the entire startup disk. Use it if your concern is protecting everything if the Mac is lost or stolen, not just one folder.
Backups See the DMG as One File
Time Machine and cloud backups can copy the .dmg file, but they cannot inspect its contents while locked. Keep the password in a secure password manager.
Sources
- Apple Support: Create an encrypted disk image with Disk Utility on Mac
- Apple Support: Encrypt files and folders on Mac
- Apple Support: Turn on FileVault on Mac