When it comes to choosing an external hard drive to use with both Windows PCs and Macs, the file system format is an important consideration. Not all hard drive formats are universally compatible between operating systems. The good news is that there are some external hard drive formats that provide compatibility with both Windows and macOS.
FAT32 – Compatible but Limited
FAT32 (File Allocation Table) is one of the most widely compatible file systems. It can be read and written to by all modern versions of Windows and macOS. However, FAT32 does have some limitations:
- Individual file size limit of 4GB
- Total volume size limit of 2TB
- Lack of built-in security features
- No journaling which can lead to greater risk of data corruption
FAT32 can be a good option for smaller external hard drives up to 2TB in size. But for larger drives and better performance, other formats should be considered.
exFAT – Compatible with No Limits
exFAT (Extended File Allocation Table) was introduced in 2006 and is optimized for flash drives. It removes the limitations of FAT32, supporting much larger file and partition sizes. Pretty much any size hard drive will work with exFAT formatting. Key advantages include:
- No file size limit
- No volume size limit
- Built-in volume allocation table checksums for improved data integrity
- Useful for large external hard drives and flash drives
The only real downside to exFAT is the lack of journaling. But it is widely supported on both Windows and macOS.
NTFS – Windows Default Format
NTFS (New Technology File System) is the default format for internal and external hard drives on Windows. It offers a modern file system with good performance and lots of features including:
- Support for very large volumes and large files over 4GB
- Security permissions and encryption
- Improved reliability through journaling
- Efficient storage through compression
- Support for data integrity checksums
NTFS has been the default Windows file system since Windows NT and offers full read/write access on all Windows versions. But NTFS read/write support is limited on macOS. Therefore NTFS is best suited for external hard drives that will mainly be used with Windows.
HFS+ – macOS Default Format
HFS+ (Hierarchical File System Plus) is the equivalent default file system for macOS. Like NTFS, it also offers modern features including:
- Journaling for improved reliability
- Support for large volumes and large files
- Permissions and encryption
- Efficient use of storage space
HFS+ volumes can be read by Windows computers, but cannot be written to without third party software. So like NTFS, HFS+ works best for external hard drives destined mainly for macOS use.
APFS – Modern macOS Replacement
APFS (Apple File System) is the newer Apple-designed file system that replaced HFS+ in macOS 10.13 High Sierra. It builds on the strengths of HFS+ while also improving SSD performance. Key highlights include:
- Optimized for Solid State Drives (SSDs)
- Faster metadata operations
- Advanced data integrity checks
- Space sharing and cloning capabilities
- Improved file system snapshots
APFS is not readable by Windows and is suited for internal SSD system drives on modern Macs. It is less relevant for external hard drives used with both Mac and Windows.
Compatibility Summary
Here is a summary of compatibility for the main hard drive formats:
| Format | Mac Read/Write | Windows Read/Write |
|---|---|---|
| APFS | Full Access | No Access |
| HFS+ | Full Access | Read Only |
| NTFS | Read Only | Full Access |
| exFAT | Full Access | Full Access |
| FAT32 | Full Access | Full Access |
Use exFAT For Flexibility
As the above table shows, only exFAT and FAT32 provide full read/write access on both macOS and Windows. But FAT32 comes with file size and volume size limitations.
Therefore, for an external drive that will be used frequently between Mac and Windows, the best option is exFAT formatting. It overcomes FAT32 limits while still providing universal compatibility.
Use NTFS for Windows-Only Drives
If you intend to use your external hard drive exclusively with Windows PCs, NTFS is a good choice. It is the native Windows file system, supporting all Windows versions and providing the best performance and most features.
Use HFS+ for Mac-Only Drives
Likewise, if the external drive will only be connected to Macs, Apple’s HFS+ format makes sense. It integrates tightly with macOS and offers full compatibility with Time Machine backups.
Use FAT32 as a Legacy Format
These days FAT32 is best reserved for small USB flash drives up to 32GB in capacity. All operating systems still support it, but there are much better options for larger external hard drives.
Formatting Considerations
When formatting an external hard drive, there are a few quick tips worth mentioning:
- Always safely eject and disconnect the drive before formatting
- Back up any important data first
- Use the native disk utility in your OS for formatting
- Quick format is fine for external drives
- Pick the right allocation unit size for optimal performance
And if sharing frequently between OSes, exFAT is highly recommended.
Useful File System Format Utilities
There are also several free third party tools available for both Mac and Windows that can format external drives using any of the file systems discussed.
On Windows, some popular utilities include:
- MiniTool Partition Wizard
- AOMEI Partition Assistant
- EaseUS Partition Master
- Rufus
And on Mac, options include:
- Fdisk
- Disk Utility
- DriveDX
- iBoysoft NTFS for Mac
These tools provide extra options for managing partitions, aligning sectors, performing recovery, and file system conversions.
Conclusion
To use a single external hard drive between both Mac and Windows, the best solution is exFAT formatting. It universally works on all versions of both operating systems with no limitations.
For drives reserved for a single OS, NTFS is ideal for Windows-only disks and HFS+ makes the most sense for Mac-only disks. FAT32 has broad compatibility but should be reserved for smaller USB flash drives.
With so many formats to choose from, cross-platform compatibility is achievable. The right file system format ensures external hard drives can easily be used to transfer and share data between Mac and Windows.
