Do hard drives have to be formatted for Mac?

Formatting a hard drive refers to preparing the drive for initial use by erasing existing data and configuring it with a file system. This process wipes the drive clean, removing all files and past data so that it’s ready to be used again with a fresh slate. Formatting is an essential step when setting up a new hard drive, allowing you to efficiently organize and store files in the future. It also optimizes the drive’s performance since the old file structure is replaced with an empty organized format.

There are some key reasons why formatting is necessary when preparing a hard drive for use with a computer:

  • Removes any existing data or leftover files from previous use (
  • Configures the drive with the correct file system for the operating system, like HFS+ for Mac or NTFS for Windows
  • Structures the drive so files can be easily saved, located and accessed
  • Enhances performance by clearing old file structures
  • Prepares the drive for efficient storage and organization of files

In summary, formatting completely wipes and reorganizes a hard drive so it’s clean and ready for the intended operating system and usage.

Differences Between Mac and Windows Formatting

The main difference between formatting a drive for Mac versus Windows is the file system. Macs use the HFS+ (also known as Mac OS Extended) file system by default, while Windows PCs use the NTFS file system.

HFS+ has been the primary file system for Macs for over 20 years. It allows Macs to store and organize files in a hierarchical structure. HFS+ supports larger partition sizes and more files than its predecessor HFS. However, it lacks some modern features like file-level encryption and recovery tools.

NTFS, which stands for New Technology File System, is the newer, more advanced default file system for Windows. It includes important features like security permissions, encryption, compression, and error recovery. However, NTFS does not work natively with Macs without third-party software.

In general, experts recommend formatting a drive with HFS+ for use exclusively with Macs and NTFS for Windows. To share external drives between Mac and Windows, the exFAT file system is ideal. It has broader compatibility, but lacks some key features offered by HFS+ and NTFS1.

When to Format a New Hard Drive for Mac

Formatting is necessary to prepare new internal or external hard drives for use with your Mac. While pre-formatted external hard drives can typically be plugged in and used right away, it’s often best to reformat them to the optimal file system for your needs.

New internal hard drives and solid state drives always need to be formatted before they can be used as a startup disk or storage drive. The Mac will not recognize an unformatted internal drive.

According to Apple’s Disk Utility guide, reformatting completely erases all content on the drive and allows you to choose a file system, partition scheme, volume format, and name. This process preps the drive for use as a clean slate.

While pre-formatted external drives for Mac can work right out of the box, reformatting lets you select a file system better suited for your needs. For example, you may want to optimize for Time Machine backups, storage across Mac and PC, or max compatibility.

In most cases, it’s best to format new internal and external hard drives before using them with your Mac. This ensures maximum performance and control over how the drive functions.

How to Format a Hard Drive for Mac Using Disk Utility

Formatting a hard drive for Mac using Disk Utility is a fairly straightforward process. Here is a step-by-step guide:

  1. Connect the external hard drive to your Mac via USB, Thunderbolt, or FireWire.

  2. Open Disk Utility on your Mac. The easiest way is to use Spotlight Search and type in “Disk Utility”.

  3. In the sidebar in Disk Utility, select the hard drive you want to format.

  4. Click “Erase” along the top menu bar.

  5. Choose a format for the drive from the dropdown menu. Common formats for Mac include Mac OS Extended (Journaled) and APFS.

  6. Give the drive a name.

  7. Make sure the format is set to “GUID Partition Map”.

  8. Click “Erase” to start the formatting process.

Formatting the drive can take several minutes depending on its size. Once completed, the external hard drive will be formatted and ready to use with your Mac.

For more details, refer to Apple’s support guide: Erase and reformat a storage device in Disk Utility on Mac.

Choosing a File System

When formatting a drive for Mac, you have a few different file system options to choose from. The main options are:

  • APFS (Apple File System) – This is the default file system for Macs with macOS 10.13 or later. APFS offers strong encryption, space sharing, snapshots, fast directory sizing, and improved file system fundamentals. It is optimized for solid state drives. According to EaseUS, APFS is one of the best file systems for Mac.
  • HFS+ (Mac OS Extended) – This is the predecessor to APFS. It works with older versions of macOS. HFS+ allows you to format the drive as journaled which adds some data integrity features. According to EaseUS, HFS+ is also a top choice for Mac file systems.
  • exFAT – This file system allows the drive to be read and written on both Macs and PCs. It does not have the more advanced features of APFS or HFS+ though. exFAT is a good option for external drives that need to be cross-platform compatible.

For most Mac users today, APFS is recommended as it is the modern Mac file system. However, if you need your drive to also work with Windows PCs, exFAT is likely the better choice. HFS+ is best reserved for older Macs running OS versions before macOS 10.13 High Sierra.

Preparing a Hard Drive for Both Mac and PC

If you want to use the same external hard drive between a Mac and Windows PC, the best file system format to use is exFAT. exFAT is optimized for flash drives and external hard drives, allowing both Mac OS and Windows to read and write files, unlike FAT32 which can only handle files up to 4GB in size (source).

To format a drive as exFAT in macOS, open Disk Utility and select the drive. Click Erase, then choose exFAT and click Erase again. In Windows, open Disk Management, right-click the drive, select Format and choose exFAT (source).

One downside to exFAT is lack of full support for permissions and file attributes compared to Mac OS Extended or NTFS. However, it provides the widest compatibility between Mac and Windows without needing third-party software.

When Not to Format a Hard Drive

There are some cases where formatting a hard drive should be avoided:

If the drive contains important personal files or data that has not been backed up – formatting will erase everything on the drive so this data would be lost permanently. It’s best to try recovering the data first before formatting in this case.

If the drive has developed bad sectors – formatting won’t fix bad sectors, and may further damage the drive. It’s better to run drive diagnostics and try to repair the bad sectors first.

If the drive is having performance issues – formatting should not be the first troubleshooting step. Issues like fragmentation or corrupted system files can often be fixed without erasing the entire drive.

If you need to access files from both Windows and Mac – formatting with Windows or Mac file systems will make the drive incompatible for sharing between operating systems. Try a cross-platform file system like exFAT instead.

If the drive is used for backup storage – formatting will delete all backup images, defeating the purpose of the backup drive. Only format as a last resort if backups are redundant.

In general, only format hard drives when absolutely necessary, like when installing a new drive or repurposing an old one. Avoid formatting just to troubleshoot minor performance issues.

Reformatting vs Erasing a Hard Drive

There is an important difference between reformatting a hard drive and completely erasing its data. Reformatting simply rewrites the hard drive’s file system, which allows it to be used by an operating system. The reformatting process does not actually touch any of the existing data on the drive (Source). The data remains intact until it is overwritten by new data.

In contrast, completely erasing a hard drive wipes all data by overwriting the entire drive with zeros or random data. This makes it impossible to recover the erased data. Simply reformatting a hard drive does not prevent recovery of the “deleted” files. To securely erase all contents, you need to use a dedicated hard drive wiping tool or service.

So in summary, reformatting simply resets the file system while leaving the existing data untouched. Only a full drive erase actually deletes data by overwriting it. Reformatting alone is not sufficient to prevent recovery of deleted files.

Tips for Formatting External Hard Drives

When it comes to formatting external hard drives that you plan to use as portable storage between Mac and Windows computers, there are some best practices to follow:

Choose the exFAT file system – This format works with both Mac and Windows right out of the box. exFAT lacks some more advanced features but is a reliable go-between.

Back up your data first – When reformatting a drive, all data will be erased. So make sure anything important is backed up elsewhere before proceeding.

Use the Disk Utility app on Mac – Disk Utility provides a straightforward way to erase and reformat external drives on Mac OS. Open Disk Utility, select the drive, choose exFAT, name it, then click “Erase”.

Quick format for portability – When given the choice between a standard or quick format, choose quick. This skips scans for bad sectors, making it faster when you just want a simple cross-platform format.

Eject safely – Always properly eject an external drive before unplugging it from your Mac to avoid data loss or corruption.

Create separate partitions if needed – If you want partitions for Time Machine or Boot Camp on the external drive, do that before formatting exFAT. The exFAT volume can then be one partition.

Label your drive – Rename your external drive something descriptive so you can easily find it on each system.

Learn disk health – On Macs, use First Aid in Disk Utility to check for and repair issues on your drive.[1]


Here are some commonly asked questions about formatting hard drives for Mac:

Do I need to format a new external hard drive before using it with my Mac?

Yes, it is recommended to format any new external hard drive for Mac before using it. This will ensure full compatibility and proper file system formatting.

What file system should I use to format my external hard drive for Mac?

Apple recommends using the APFS or Mac OS Extended file systems when formatting an external hard drive for use with Macs. Both of these are optimized for macOS.

Can I use an NTFS formatted external hard drive with my Mac?

Yes, you can use an NTFS formatted drive with Mac but will need additional software for full read/write capabilities since Mac can only read NTFS by default. Some options are Paragon NTFS or Tuxera NTFS.

Is formatting the same as erasing a hard drive?

No, formatting and erasing are different. Formatting prepares the hard drive by creating a file system and structure for the OS. Erasing deletes all data on the drive and resets it to a blank state.

How do I reformat an external hard drive that is already formatted for Mac?

You can reformat an external hard drive using Disk Utility. Simply connect the drive, open Disk Utility, select the drive, click Erase, choose the format, and erase the drive.