Formatting A External Drive For Mac

External drive connected to your Mac. Time Machine can back up to an external drive connected to.

The best format for video production is exFAT. The maximum individual file size for exFAT is 16 EB. 1 EB, or exabyte, is 1 billion GB. That said, if you are using smaller file sizes — FAT32 can suffice. Format Hard Drive (Mac) 1. Connect the external hard drive to the computer. How to Format External Hard Drive on a Mac? Now, I will show you how to format external hard drive on a Mac using the below steps. As we can format the drive from Disk utility, Therefore, we will do it with the disk utility option. Step 1: Connect the external hard drive to your Mac that you want to format. These steps can be used for both internal and external drives. Reformatting the drive will erase all data on the drive, so you should copy any data you want off the drive prior to formatting. The following is based on Mac OS X version 10.10.5. However, the steps are suitable for Mac OS X 10.6.8 to 10.10.5.

By Juno Posted to NTFS for Mac Tips, updated on September 3rd, 2020

It's important to know how to format an external hard drive for your Mac and PC before you use it to free up space and transfer files between computers. If you don't format the external hard drive correctly, it won't work to the utmost extent. For instance,Windows uses NTFS, while Mac uses HFS+ or APFS. Out of the box, Windows can't read or write to HFS+/APFS drives and Macs can't write to NTFS drives either.

Though the default hard disk file system (also known as format) of Windows and Mac are different, there should be some ways to format an external drive for both Mac and PC. After reading this post, you'll know what is the best file system for your camera's SD card and what is the best format for your Mac and PC. More importantly, you will know how to format flash drives for Mac and PC and make hard drives compatible with macOS and Windows.

Table of contents
1. Common File Systems for Mac and PC
2. How to format external hard drives for Mac and PC?
3. How to partition an external hard drive for Mac and Windows PC?
4. Make external hard drives compatible with Mac and PC without formatting

Common File Systems for Mac and PC

The file system is one of the most important part for an external hard drive because it manages how your files are stored and retrieved. So, every hard disk needs a proper file system, including desktop drives and portable storage devices like external hard drives, USB flash drives and SD cards. However, different file systems have different advantages and disadvantages. So before you know how to format a hard drive, you should know the pros and cons of each file system.

1. FAT32

FAT file system includes three major file system variants but the majorly used one is FAT32. FAT32 is commonly used in floppy disks, SD memory cards, USB flash drives, digital cameras, as well as many portable and embedded devices.


  • Works universally with all versions of Mac, Windows, Linux, game devices, as well as other devices supporting a USB port.


  • Doesn't support a file size larger than 4GB and a drive partition size larger than 32GB on Windows.
  • Doesn't support the drive partition larger than 2TB on macOS.

2. exFAT

exFAT is a good option for external hard drives (e.g. Seagate Backup Plus Slim), especially for large-capacity removable storage devices. It also is frequently used in flash memory drives such as USB flash drives and SD cards. exFAT is easily often implemented in firmware that has low memory and low power requirements, such as cameras, mobile phones, media players, etc.


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


  • Not compatible with too much old operating systems.
  • Not a good option for drives less than 32GB because it can't maximize space utilization.


NTFS is a proprietary journaling file system developed by Microsoft. It is used as the default file system of Windows system hard drive (e.g. Windows 10). NTFS does well in data security based on its encryption, access permission control, and log file.


  • Improved performance, reliability, and disk space use.
  • Performs better in protecting data security, data management.
  • Compatible with all versions of Windows and latest hardware.


  • Read-only in macOS and the disabled-by-default write support for NTFS in macOS is unstable.

4. Mac OS Extended (HFS+)

HFS Plus or HFS+ is a journaling file system developed by Apple Inc. It's the startup disk’s default file system before macOS High Sierra. It also frequently used as Time Machine backup external hard drives of WD, Seagate, etc.


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


  • Has no access permission control.
  • Perfoms slow or crash in dealing with a large number of files.
  • Harder for data recovery when an HFS+ hard drive is corrupted.

5. Apple file system (APFS)

APFS is the new proprietary file system of Apple. It has been known to increase read/write speeds on solid-state drives (SSDs), as well as increase storage space due to the way in which it calculates the available data on disk.


  • Allows full-disk encryption with single or multi-key encryption for added security.
  • Efficient in management of free storage space


  • Not good for Time Machine backup due to no support for hard links to directories.
  • Can only be used on macOS 10.13 and above.

After knowing their unique specifications, it becomes easier to choose the best file system for your storage device. For instance, you would know why exFAT is better for camera SD cards, or why NTFS is better for external backup drive on Windows 10. In a word, you can format or reformat your external hard drive per your requirement, either for Mac and PC.

Warning: Formatting will erase data on this drive. So, if you have important files on this external hard drive, make sure you have a backup. However, if you have formatted this drive and lose files, you can recover lost data from formatted external hard drive with iBoysoft Data Recovery for Mac.

How to format external hard drives for Mac?

To format external hard drives on Mac, you'll need the built-in disk management tool called Disk Utility. Then, you need to choose the best file system for your external hard drive when erase it.

Tips: Remember to back up the files on the external hard drive if you have saved anything important on it.

• Guide to format external hard drive on Mac computer.

How to format external hard drives for Windows computer?

Similarly, you can also format your drive on Windows computers with a utility called Disk Management.

Tips: To prevent data loss during formatting, make sure you haven't saved important files on the drive. If you have, backup them first.

• Guide to initialize and format external hard drive on Windows computer.

How to format an external hard drive for Mac and PC?

Sometimes, users need to use the same external hard drive interchangeably on Mac and PC. To make it compatible with both macOS and Windows, you need to reformat the external hard drive.

Whether you are using an APFS/HFS+ or a Windows NTFS formatted external hard drive on Mac, you can reformat the external hard drives for both Mac and PC. File systems like FAT32 and exFAT can make the external HDD compatible with both Macs and Windows PCs.

Warning: Reformatting will wipe files off the external hard drive. So, you should make sure you have backed up your files on the external hard drive before you continue any steps.

When should you choose FAT32 file system?

FAT32 works with almost any operating system as well as video game consoles, Android USB expansions, media players, and other devices. However, FAT32 can only support files up to 4 GB in size. So, If all your files on the external hard drive are smaller than 4 GB, and the drive itself is smaller than 2 TB, then FAT32 is a better choice for you to use the hard drive on Mac and PC.

When should you choose exFAT file system?

Similarly, exFAT is also a widely compatible file system. The difference is that exFAT has no limitations on file size and hard drive size. So, when the external HDD you want to used for both Mac and PC is larger than 2 TB, exFAT is the best choice.

After you choose the best format for your drive, you can format or reformat the external hard drive in Disk Utility as it was introduced. Then the external hard drive will work both for Mac and PC.

When should you choose NTFS file system?

Some users would prefer to the features of Windows NTFS file system. However, naturally, Disk Utility can't format external hard drive to NTFS. If you want an hard drive that you can only read on Mac but have full access on Windows, NTFS is the best choice. You can also use iBoysoft NTFS for Mac to reformat the external hard drive with NTFS on Mac.

  1. Step 1: Download and install iBoysoft NTFS for Mac on your Mac.
  2. Step 2: Connect the external hard drive to your Mac and launch this software.
  3. Step 3: Find Disk Management in its main menu and click on it.
  4. Step 4: Locate the volume you want to reformat, select it, and then click on Erase to NTFS.

What to do if you can’t format the external hard drive on Mac?

Usually, to format the external hard drive as FAT32 or exFAT, you are advised to do this on a Mac computer via Disk Utility. But if you have formatted the external hard drive under the Windows system, it would cause some inconvenience. You can't add or re-partition volumes of the external hard drive again on Mac. In this case, your only choice is to backup your files and reformat the whole disk.

How to partition an external hard drive for Mac and Windows PC?

Except for having the whole external hard drive formatted, you can also split this disk with two partitions. One is formatted with the file system that is compatible with macOS, another partition is compatible with Windows conversely. By this means, you can use all the advantages each format has on the respective system.

Warning: Still, you need to back up files on this drive before you begin to create two separate partitions to work for Mac and Windows PC.

For some Mac models, the partition option would be greyed out in Disk Utility. So, we suggest that it's better to use a PC to partition an external hard drive for macOS and Windows. Here are the steps to partition an external hard drive for Mac and Windows PC, which is a little tricky.

Step 1: Connect the external hard drive to your PC and then launch Disk Management.

Step 2: Check if the external hard drive is initialized or not.

If the drive is not initialized, you need to initialize the external hard drive with Master Boot Record (MBR). Then you can create two new partitions. You need to format one of them as NTFS for Windows use and format the other as your wish.

If the external hard drive is initialized, you need to right-click the disk to check if it's an MBR external hard drive.

  • If you see Convert to GPT Disk in the context menu, be it greyed out or lighted, it’s an MBR hard drive. Then you can create two or more partitions. And you need to prepare one partition for NTFS file system, and reformat with any file system.
  • If you see Convert to MBR Disk in the menu, it's an GPT hard drive. In this case, you need first backup files, delete the existing partitions, then click the Convert to MBR Disk button. Then, you can create two new partitions. You need to format one partition as NTFS for Windows use, and then format the other randomly.

Step 3: Up to now, there should be at least two partitions on the external hard drive. And one of them (the NTFS one) is ready for Windows use. Then, you need to safely remove the external hard drive and plug it into a Mac.

Step 4: Open Disk Utility and select the other partition (not the NTFS one) under the name of your external hard drive.

Step 5: Click Erase on the top, choose Mac OS Extended format when it asks, and chose Erase to finish.

Up to now, the external hard drive will have two partitions. One is HFS+ formatted for Mac, and the other is NTFS formatted for Windows.

By creating two separate partitions, you can use this external hard drive on both Mac and Windows. You won't be able to write to the Mac partition from your Windows computer, and vice versa. Thus, it's a good solution for people who need to swap between two operating systems but with separate work.

Make external hard drives compatible with Mac and PC without formatting

Many famous external hard drives like Seagate Backup Plus Ultra Touch and WD My Passport are pre-formatted with NTFS. However, the NTFS file system is a hassle for users who need to use the same external hard drive on both Mac and Windows. The external hard drive is not letting you add files if you use an NTFS external HDD on Mac. It will be read-only and you can't write to this drive normally in this case.

Many users don't know this and use the external hard drive directly. And when they want to reformat the hard drive to use it interchangeably, only to find that files on the drive are erased as well.

Then, can you solve external hard drive read-only without formatting?

Definitely! If you want to use NTFS formatted external hard drives on Mac, software like iBoysoft NTFS for Mac that might be helpful.

iBoysoft NTFS for Mac - professional NTFS driver for Mac

iBoysoft NTFS for Mac is a professional NTFS for Mac software, which can automatically mount NTFS drives in read-write mode on Mac. It supports macOS Catalina 10.15/Mojave 10.14/High Sierra 10.13/Sierra 10.12 and Mac OS X El Capitan 10.11/Yosemite 10.10/Mavericks 10.9/Mountain Lion 10.8. With this useful tool, you'll have full access to NTFS drives on Mac and make your external hard drive interchangeable between Macs and PCs without formatting. Also, you can mount and unmount NTFS drives from the Mac menu bar with advanced and optimized options.

What's more, iBoysoft NTFS for Mac is also a handy tool to manage NTFS external drives. You can use it to easily mount, unmount, repair, erase NTFS external hard drives, USB flash drives, SD cards, memory cards, CF cards, pen drives, etc. on Mac.

Tutorial to mount NTFS external hard drive on macOS with read-write mode with iBoysoft NTFS for Mac

Step 1: Free download, install, and launch iBoysoft NTFS for Mac on your computer.

Step 2: Connect your NTFS external hard drive to Mac, and iBoysoft NTFS for Mac will automatically mount it.

Step 3: Write to NTFS external hard drive after the disk has been mounted in read-write mode successfully.

If you want to use HFS+ or APFS formatted external hard drives on Windows, you can also attempt to install HFS+ for Windows software or APFS for Windows software on your PC to get read and write access to this external hard drive.


To sum up, it is easy to format an external hard drive for both Mac and Windows PC. You can either choose to format the whole disk as exFAT/FAT, or you can create two separate partitions of HFS+ and NTFS if you prefer. But compared with formatting, an NTFS for Mac driver like iBoysoft NTFS for Mac is a better and feasible solution.

Yo just got a new external hard drive and want to use it on your Mac. However, the Mac OS does not allow you to write data to the drive. You may wonder how to reformat an external hard drive on Mac. Follow the tutorial below, you'll get everything covered.

  • Bonus: How to Recover Data from Formatted External Hard Drive on Mac

Reformatting an external hard drive for use with Mac OSX is not as difficult as it might seem. In a few simple steps you are ready to go and can save your back-up files to the external drive, keeping your information safe and giving you peace of mind. Keep in mind that a MAC can generally read other file formats, but for the best performance and to create a bootable disk, formatting exclusively for MAC is required.

Part 1: Which File Format You Should Choose?

Before you begin formatting the drive, there are a few things to do. The most important, you should decide which format to use.

There are a few file formats you can use, but it depends on the purpose you want to use the drive for. Which one is right for your circumstance? We'll describe them here, you'll know your choice after reading the details.

APFS: This is the default file system in Macs with High Sierra. It is efficient and reliable. However, it won't be readable and usable on machines that are not running Mac High Sierra, and Windows or Linux PCs. What's more, it is compatible with SSD and flash storage devices only.

Mac OS Extended (Journaled/HFS+): If you didn't update your Mac OS to High Sierra, the default file system on your Mac shoule be Mac OS Extended. Mac OS Extended (encrypted) would be an ideal option if you probably carry your laptop or external drive here and there. You can encrypt it so that no one can access the contents on your drive.

MS-DOS FAT (aka FAT32): In addition to Mac, it can also be written and read by Linux and Windows. It enables you to regularly share files with your friends who own a PC. Nevertheless, this older file system is limited to no more than 4GB and there might be security issue and disk errors.

ExFAT: It is similar to ExFAT which can be read by both Windows and Mac, but it can store more than 4GB files.

NTFS: As the default file system in Windows, it can only read by Mac OS, writing to it is not available. Luckily, there are third-party tools to help you do so.

Part 2: Format External Hard Drive for Mac with Disk Utility

Formatting an external hard drive would erase everything on it. Hence, you must backup your important files before reformatting the drive if you want to save them. The easiest way is to drag it from one drive to another.

All is set, then you can go ahead to format the drive on your Mac. Disk utility - the MacOS utility application can help you with this. Just follow these steps below:

Step 1. Connect the external drive or the USB drive to the MAC.

Step 2. Start the Disk Utility, located under Applications > Utilities.

Step 3. Find the name of the drive in the left side of the Utilities window and select it. And click Erase button.

Step 4. Follow on-screen prompts to choose Mac OS Extended (Journaled) file system and allow the disk to format.

Bonus: How to Recover Data from Formatted External Hard Drive on Mac

In case you forgot to backup files before formatting the external drive. Here comes the cure - iMyFone AnyRecover - a one-stop solution to recover deleted, lost or formatted files from Mac.

Follow these simple steps using AnyRecover to get your files back!

Get Ready!

First, download and install AnyRecover, following on-screen prompts to accomplish the task.

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Get Set!

Mac And Windows Compatible Format

  • 1. After loading AnyRecover, plug your external hard drive into your Mac directly or via USB.

  • 2. Next select the drive under 'External Removable Devices' tab, click 'Start' to begin scanning lost files on the drive.


Mac Formatting Software

  • 1. AnyRecover takes a moment to scan your drive. Once done, it will list out all scanning results by file type.

  • 2. Double click a single file to preview it before recovery.

  • 3. Select the files and press Recover to get them back.

What If?

What if my files were not found? Fear not. We can take this a step further. Enable 'Deep Scan' to try one more time, follow the steps above just as before to locate and recover your files.

It is plain to see that AnyRecover for Mac is a tool worthy of top shelf treatment in your arsenal of items that are used to defend, recover and keep your system up and running. Don't get caught without the file you need for that meeting or stumbling looking for baby photos that were stored on disk and suddenly 'hid' from your view. Allow AnyRecover to find and recover your lost files. AnyRecover is easy to use but provides sophisticated results that mean you know what you're doing!