How to encrypt files on Mac in 2025

Encrypting files on your Mac is essential for protecting sensitive information like financial documents, legal contracts, or personal data. Whether you're securing individual files or your entire disk, macOS provides built-in encryption tools that use strong cryptographic algorithms to protect your data from unauthorized access.

When you encrypt files on Mac, macOS uses AES encryption to transform your data into unreadable code that can only be decrypted with the correct password or key. Understanding which files need encryption helps you prioritize security efforts for sensitive documents. This guide covers multiple methods to encrypt files on Mac, from full disk encryption to individual file protection.

Quick recap of Mac file encryption methods

1. FileVault: Full disk encryption for your entire Mac startup disk
2. Disk Utility encrypted images: Create password-protected disk images for folders and files
3. PDF encryption: Password-protect individual PDF documents
4. Secure file sharing: Use cloud-based platforms for encrypted file sharing with additional features
5. Third-party encryption tools: Use specialized software for advanced encryption needs

Method 1: Using FileVault for full disk encryption

FileVault encrypts your entire startup disk, automatically protecting all files on your Mac with XTS-AES-128 encryption. Once enabled, all files are encrypted and decrypted transparently as you use your Mac.

Step-by-step guide for enabling FileVault:

1. Open System Settings:
   • Click the Apple menu (🍎) in the top-left corner
   • Select System Settings (or System Preferences on older macOS)
   • Click Privacy & Security
   • Scroll down to FileVault

2. Enable FileVault:

   • Click the lock icon (🔒) to make changes
   • Enter your administrator password
   • Click Turn On FileVault

3. Choose recovery method:

   • Use iCloud account: Allows you to unlock your disk using your Apple ID
   • Create a recovery key: Generates a unique recovery key you must store securely
   • Choose the option that works best for you

4. Store your recovery key:

   • If you chose to create a recovery key, macOS will display it
   • Write it down and store it in a secure location
   • You'll need this key if you forget your password
   • Click Continue after storing the key

5. Restart your Mac:

   • macOS will prompt you to restart
   • The encryption process begins after restart
   • Initial encryption may take several hours depending on disk size
   • You can continue using your Mac during encryption

Important notes: FileVault encrypts your entire startup disk, including system files, applications, and user data. Once enabled, you must enter your password or use your recovery key to unlock your disk when starting your Mac. The encryption is transparent—files are automatically decrypted when you're logged in and encrypted when you're not.

Security benefit: FileVault protects all files on your Mac, including deleted files that haven't been securely erased. If your Mac is lost or stolen, the encrypted data cannot be accessed without your password or recovery key.

Method 2: Creating encrypted disk images with Disk Utility

Disk Utility allows you to create encrypted disk images—password-protected containers that you can mount like external drives. This method is ideal for encrypting specific folders or files without encrypting your entire disk.

Step-by-step guide for encrypted disk images:

1. Open Disk Utility:

   • Go to Applications > Utilities > Disk Utility
   • Or press Command + Space and type "Disk Utility"

2. Create a new disk image:

   • Click File > New Image > Blank Image
   • A dialog box will appear

3. Configure the disk image:

   • Name: Enter a name for your encrypted disk image
   • Size: Set the size based on your needs (e.g., 1 GB, 5 GB, 10 GB)
   • Format: Choose APFS (recommended) or Mac OS Extended (Journaled)
   • Encryption: Select 128-bit AES encryption or 256-bit AES encryption (recommended)
   • Partitions: Choose Single partition - GUID Partition Map
   • Image Format: Select read/write disk image

4. Set a password:

   • Click Save
   • Enter a strong password in the password field
   • Confirm the password
   • Optional: Check "Remember password in my keychain" to avoid entering it each time
   • Click Choose to create the disk image

5. Use the encrypted disk image:

   • The disk image appears on your desktop or in Finder
   • Double-click the .dmg file to mount it
   • Enter your password when prompted
   • The encrypted volume mounts like an external drive
   • Drag files and folders into the mounted volume
   • Eject the volume when done to secure your files

Best practices: Use strong passwords with at least 16 characters, mixing uppercase, lowercase, numbers, and special characters. Store the password securely, as you cannot recover files from an encrypted disk image without it. For detailed guidance on password-protected encryption, see our guide on how to encrypt a file with a password.

Method 3: Encrypting existing folders

You can convert existing folders into encrypted disk images, protecting all files within the folder.

Step-by-step guide for encrypting folders:

1. Open Disk Utility:

   • Go to Applications > Utilities > Disk Utility

2. Create image from folder:

   • Click File > New Image > Image from Folder
   • Select the folder you want to encrypt
   • Click Choose

3. Configure encryption settings:

   • Name: Enter a name for the encrypted disk image
   • Encryption: Select 128-bit AES encryption or 256-bit AES encryption
   • Image Format: Choose read/write disk image
   • Click Save

4. Set password:

   • Enter a strong password
   • Confirm the password
   • Click Save

5. Secure the original folder:

   • After creating the encrypted disk image, securely delete the original folder
   • The encrypted .dmg file now contains all your files
   • Mount the disk image when you need to access files

Use case: This method is ideal for encrypting project folders, document collections, or backup archives that you want to protect with password encryption.

Method 4: Password-protecting PDF files

macOS Preview allows you to encrypt PDF documents with password protection, securing individual PDF files without creating disk images.

Step-by-step guide for PDF encryption:

1. Open the PDF in Preview:

   • Right-click the PDF file
   • Select Open With > Preview
   • Or double-click the PDF to open it in Preview

2. Export with encryption:

   • Click File > Export
   • Choose a location to save the encrypted PDF
   • In the Format dropdown, ensure PDF is selected

3. Enable encryption:

   • Check the "Encrypt" checkbox
   • A password field will appear
   • Enter a strong password
   • Confirm the password

4. Save the encrypted PDF:

   • Click Save
   • The PDF is now password-protected
   • You can delete the original unencrypted PDF if desired

Note: Preview uses AES-128 encryption for PDF password protection. For stronger security, consider using Adobe Acrobat or creating an encrypted disk image containing the PDF.

Method 5: Using secure file sharing platforms

For sharing encrypted files with others, cloud-based secure file sharing platforms provide encryption plus additional features like access controls, analytics, and the ability to revoke access.

Step-by-step guide for secure file sharing:

1. Upload your file to a secure platform:
   • Use Papermark or another secure file sharing service
   • Upload your sensitive document
   • The file is automatically encrypted with AES-256 encryption

2. Configure security settings:
   • Enable password protection for the document
   • Set access expiration dates if needed
   • Enable email verification to require recipient identity confirmation
   • Configure allowlist/denylist to control who can access

3. Share the encrypted file:
   • Generate a secure link
   • Share the link via email or messaging
   • Provide the password through a separate, secure channel

Benefits: This method provides encryption plus access tracking, analytics, and the ability to revoke access even after sharing. It's ideal for sharing sensitive files with clients, partners, or team members. Learn more about which files need encryption to determine when to use this approach.

Share encrypted files securely

Comparison: Mac file encryption methods

Best practices for encrypting files on Mac

Follow these practices to maximize the security of your encrypted files on Mac.

1. Use strong passwords: Create passwords with at least 16 characters, mixing uppercase, lowercase, numbers, and special characters. Use unique passwords for different encrypted files or disk images.

2. Store passwords securely: Use a password manager to store encryption passwords. Never store passwords in unencrypted text files or share them in the same message as encrypted files.

3. Enable FileVault for full protection: If your Mac contains sensitive information, enable FileVault to encrypt your entire disk. This protects all files, including system files and deleted data.

4. Backup encryption keys: Always backup FileVault recovery keys and store them securely. If you lose your password and recovery key, you cannot recover encrypted data.

5. Use appropriate encryption strength: For highly sensitive data, use AES-256 encryption when available. AES-128 is also secure for most use cases.

6. Combine encryption methods: Use FileVault for full disk protection and encrypted disk images for specific sensitive folders or files that need additional protection.

7. Regularly update macOS: Keep your Mac updated with the latest security patches to ensure encryption features work correctly and vulnerabilities are addressed.

8. Securely delete original files: After creating encrypted versions, securely delete original unencrypted files using the "Secure Empty Trash" option or third-party secure deletion tools.

9. Test encryption before relying on it: Verify that encrypted files cannot be opened without the password before storing sensitive information. Test recovery procedures to ensure you can access encrypted files when needed.

10. Use secure file sharing for collaboration: When sharing encrypted files with others, use secure file sharing platforms that provide encryption, access controls, and tracking capabilities.

Conclusion

Encrypting files on your Mac protects sensitive information from unauthorized access, whether you're securing individual documents or your entire disk. FileVault provides comprehensive full disk encryption, while Disk Utility encrypted images offer flexible protection for specific files and folders. For sharing encrypted files, secure file sharing platforms combine encryption with password protection, access controls, and detailed analytics.

Choose the encryption method that matches your security needs, and always follow best practices like using strong passwords and securely storing recovery keys. For comprehensive file encryption with advanced security features, consider using platforms like Papermark that combine encryption with password protection, access controls, and detailed analytics.

Start encrypting your files securely

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