How format USB flash drive or external hard drive on Mac?

Posted by Tim to Mac Data Recovery Tips on March 9th, 2020

Nowadays, when you buy a USB flash drive or external hard drive, you can use it right out of the box with your Mac. However, not every USB flash drive or external hard drive can be used at once. Some USB flash drives or external hard drives have to be formatted first before you can store files. In this post, we are taking how to format USB flash drive or external hard drive on Mac.

Insert USB drive to Mac

Format USB flash drive or external hard drive with disk utility

Mac computer has a built-in utility called Disk Utility, which can be used to format any storage device.

Step-by-step tutorial to format USB flash drive or external hard drive on Mac:

1. Connect the USB flash drive or external hard drive to your Mac computer.

2. Go to Applications folder and Utilities and open Disk Utility.

You will see Disk Utility main window, with a storage device list on the left and various disk management options on the right.

At the bottom of Disk Utility main window, there are storage device details, including disk description, disk type, connection type, total capacity, write status, S.M.A.R.T. status, and partition map scheme.

3. Select USB flash drive or external hard drive from the storage device list on the left and click Erase in the Disk Utility toolbar.

Erase the drive

4. Select which file system (FAT32, exFAT, HFS+ or APFS) you want to use and give it a name.

If you're not sure which file system you should choose, find more information from "Understanding file systems" section.

If you want to format external hard drive to NTFS file system, you need to install a NTFS for Mac tool on your Mac.

5. Click on the Erase button to format USB flash drive or external hard drive. Once the formatting process is finished, you can store the files in this newly formatted USB flash drive or external hard drive.

If you mistakenly formatted a wrong USB flash drive or external hard drive, recovering lost data is possible. See the tutorial: How to recover data after format?

Understanding file systems

macOS and Windows support different file systems.

FAT32

FAT32 is commonly used in SD card, memory card, USB drive, flash drive, external hard drive, etc.

Pros:
Works well with Mac, Windows, Linux operating systems.

Cons:
Doesn't support single file larger than 4GB.
Doesn't support drive partition larger than 32GB on Windows.
Doesn't support drive partition larger than 2TB on macOS.

exFAT

exFAT is a good option for external hard drive, especially for large-capacity removable storage device. It is also used in flash drives, such as USB drive, flash drive, SD card, cameras, mobile phones, media players.

Pros:
Supports the largest partition and file sizes by today's standards.

Cons:
Not compatible with old operating systems.
Not a good option for drive less than 32GB, because it cannot maximize space utilization.

HFS+

HFS+ (Mac OS Extended) is a journaling file system developed by Apple. It is a default file system for Macintosh HD before macOS High Sierra.

Pros:
Supported by all versions of Mac OS X and macOS.
Has journaling, compression, and encryption features.

Cons:
Perfom slow or crash in dealing with a large number of files.
Diffcult for data recovery when a HFS+ hard drive is corrupted.
Not compatible with Windows operating system.

APFS

APFS is short of Apple file system. It is the new file system of Apple. It has been known to increase read and write speed on solid-state drive (SSD), as well as increase storage space.

Pros:
Allow full disk encryption.
Efficient in management of free storage space.

Cons:
Not a good option for Time Machine backup drive, because it doesn't support hard links.
Can only be used on macOS 10.13 and later version.
Not compatible with Windows operating system.

NTFS

NTFS is a proprietary journaling file system developed by Microsoft. It is used as a default file system on Windows. NTFS does well in data security based on its encryption, access permission control, and log file.

Pros:
Improved performance, reliability, and disk space usage.
Perform better in data security, data management.
Compatible with all versions of Windows and latest storage devices.

Cons:
Read-only on macOS.

After knowing these specifications, it becomes easier for you to choose the best file system for your storage device.

How to recover data after format

We all make mistakes, and you wouldn't be the first person in the world to accidentally format a storage device.

M3 Data Recovery, a data recovery software for macOS and Windows operating systems. It can help you recover deleted or lost files from USB flash drive or external hard drive, even recover lost data after format.

Step-by-step tutorial to recover data after format:

1. Download M3 Data Recovery (m3datarecovery.dmg) and install it on your Mac computer.

2. Launch M3 Data Recovery for Mac and select the formatted USB flash drive or external hard drive.

3. Check deep scan option and click Next to scan lost data.

Mac data recovery software

4. M3 Data Recovery for Mac is scanning the lost data from the formatted drive.

M3 Data Recovery for Mac scans lost files

5. After the scan completes, you can preview the documents, photos and play videos, audios. With built-in preview function, you can see if your lost files are recoverable.

Recover lost files with M3 Data Recovery for Mac

6. Select the files you need and click Recover to start recovery.

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