How to encrypt or password protect USB flash drive on Mac?

Updated by Tim to BitLocker for Mac on September 1st, 2021

Encrypting a portable USB flash drive is a great way to protect sensitive data so as no other persons except you can open and modify the files. This guide will demonstrate how to securely encrypt a USB flash drive within macOS so that the data stored on it cannot be read nor accessed without entering a secure password.

How to encrypt a USB drive on your Mac?

This article will introduce two solutions to encrypt USB flash drive on macOS Big Sur, Catalina, Mojave and High Sierra.

Option 1: Using BitLocker to encrypt a USB drive on Mac

Truecrypt is not secure. With GDPR (General Data Protection Regulation) now in full force, we have to make our drives being encrypted.

Up to now, BitLocker is the most truely secure encryption solution built-in Windows. Although Microsoft has not implemented BitLocker client for macOS, but with the help of M3 BitLocker Loader for Mac, encrypting USB flash drive with BitLocker can be done on macOS Big Sur/Catalina/Mojave/High Sierra.

If you are a cross platform user, BitLocker is the best choice to encrypt your USB flash drive and BitLocker encrypted USB flash drive can be easily accessed on Windows without an extra software.

Tutorial to password protect a USB drive with BitLocker on macOS

Step 1: Download and install M3 BitLocker Loader for Mac on your Mac computer.

Step 2: Insert USB flash drive (The file system must be NTFS, FAT32 or exFAT) into your Mac computer.

Step 3: Launch M3 BitLocker Loader for Mac.

Step 4: Click "Encrypt" button in toolbar of M3 BitLocker Loader for Mac.

M3 BitLocker Loader for Mac

Step 5: Select USB flash drive and then click Encrypt.

Encrypt USB flash drive with M3 BitLocker Loader for Mac

Step 6: Enter the password.

Enter the password

Step 7: Save the recovery key.

Save the recovery key

Step 8: After BitLocker drive encryption completes, the USB flash drive will be password protected.

Start BitLocker drive encryption on Mac

Then you can use M3 BitLocker Loader for Mac to open a BitLocker encrypted drive on your Mac and read/write it.

Option 2: Using FileVault to password protect a USB drive on Mac

FileVault is a disk encryption tool built in Mac OS X El Capitan and later version, but USB flash drive encrypted with FileVault cannot be opened by Windows. The password you choose to encrypt your USB flash drive cannot be changed once the encryption completes.

Tutorial to encrypt USB flash drive with FileVault on Mac:

Step 1: Insert your USB flash drive into your Mac computer.

Step 2: Open the Finder and right click USB flash drive in the left sidebar.

Step 3: Select Encrypt.

Encrypt USB flash drive with FileVault

Step 4: Enter the password and confirm a password.

Step 5: Encryption will take a few minutes; once complete, you USB flash drive will be fully protected with a password.