If you’ve already formatted or burned a pen drive, then you know that these procedures require choosing a format (aka file type). The FAT32 format, exFAT format, NTFS format, and HFS+ format are amongst the most popular ones. The first two are non-proprietary, which means that a USB key formatted using FAT32 or exFAT can generally be both read and written on from any operating system. As for NTFS and HFS+, their name might not necessarily ring a bell, but they are omnipresent. NTFS is the proprietary format file used by Windows, whereas HFS+ is a proprietary format used exclusively by Mac.

Besides the operating system you intend on using your pen drive on, there are more factors to consider in addition to cross-platform compatibility when choosing a format. Things like your operating system version and the size of the files you want to put on your external flash drive also have to be taken into account. Furthermore, there exist more than just the four formats presented earlier. Even though their use isn’t as prevalent, you might still come across other file types when having to select a format type during the formatting process.

Native OS formatting and partitioning tools such as Disk Utility on macOS or the integrated Formatting tool on Windows 10 usually provide less file type options than third-party software such as GParted, or Linux-based GUI partitioning tools like KDE Partition Manager or GNOME Disks (used on the KDE Plasma 5 and GNOME desktop environment, respectively). This guide will also include some of the file types you might come across when using these alternative software applications. Note that I only included the file types which can potentially be selected when formatting a pen drive.

Screenshot of the formats available on the macOS Disk Utility tool: Mac OS Extended (Journaled), Mac OS Extended (Case-sensitive, Journaled), MS-DOS (FAT32 format), ExFAT
Formats available on the macOS Disk Utility tool: Mac OS Extended (Journaled), Mac OS Extended (Case-sensitive, Journaled), MS-DOS (FAT32 format), ExFAT
Screenshot of the formats available on the Linux GParted app: ext2, ext3, ext4, FAT16, FAT32, NTFS
Formats available on the Linux GParted app: ext2, ext3, ext4, FAT16, FAT32, NTFS
Screenshot of the formats available on the Linux KDE Partition Manager app: exFAT, ext2, ext3, ext4, FAT16, FAT32, NTFS
Formats available on the Linux KDE Partition Manager app: exFAT, ext2, ext3, ext4, FAT16, FAT32, NTFS
Screenshot of the format types available on the GNOME Disks tool: Ext4, NTFS, FAT32 format
The format types available on the Linux GNOME Disks tool: Ext4, NTFS, FAT32 (and others)

This guide will categorize the format types according to the following criteria:

  • Formats compatible across all operating systems (Windows, macOS, Linux)
  • Formats only compatible with Windows
  • Formats only compatible with Mac
  • Formats only compatible with Linux

Following this classification, a brief description of the USB format types will be given, as well as their limitations.

The file types included in this article are the following:

  • FAT32
  • exFAT
  • NTFS
  • ReFS
  • HFS+
  • APFS
  • ext2
  • ext3
  • ext4
  • XFS

What about the USB flash drive?

The choice of a more modern or higher-performing file type over another is only as good as the quality of your USB key. This is why I recommend choosing a USB 3.0 or USB 3.1 pen drive if you are serious about data transfer rapidity and efficiency.

You will find below three USB flash drives that I recommend: SanDisk Ultra Flair, Kingston Digital DataTraveler and Samsung BAR Plus. I chose to mix things up a bit by showing a model for each of these three leading pen drive brands. Note that of these choices, the first two are the household names for the USB market. Samsung is better known for its internal SSD hard drives (of which I have owned two, both working seamlessly).

SanDisk is generally considered the higher-end brand when compared to Kingston Digital. However, the latter is a great economical choice and still provides reliable pen drives.

As for Samsung, I also have two of their ultra-compact 128 GB pen drives, which I’ve used for many years without any heating or performance issues. Even though Samsung USB flash drives are sometimes hit or miss, I still included this particular model as an option. The Samsung BAR Plus offers an economical way of buying a USB 3.1 while still getting a known brand.

All three pen drives have a capacity of 128 GB, with the first two being USB 3.0. If at the time of clicking these links all are at comparable prices, I recommend choosing either the SanDisk pen drive (always reliable) or the Samsung one (better performance). The final choice is up to you. Note that if you intend to use your USB stick to store sensitive data, then SanDisk might be a better choice. This brand is known for its consistency and lesser hardware-failure rate.

Note that the three links posted above are affiliate links. If you go through them to make a purchase, I will earn a commission (at no cost to you). I link these companies and their products because of their quality and not because of the commission I receive from your purchases. These links are used to pay for the cost and upkeep of ITgirl.tech. Thank you!

Formats compatible across all operating systems (Windows, macOS, Linux)

  • exFAT
  • FAT32

Formats only compatible with Windows

  • NTFS
  • ReFS

Formats only compatible with Mac

  • HFS+ (also referred to as Mac OS Extended (Journaled) or Mac OS Extended (Case-sensitive, Journaled)
  • APFS

Formats only compatible with Linux

  • ext2
  • ext3
  • ext4
  • XFS

The exFAT format

Description: The most versatile of all, the exFAT format is a filetype that was developed by Microsoft in 2006 and is usable across all operating systems. Even though the exFAT format is proprietary to Microsoft (as it owns many of its design patents), it is usable on all modern operating systems. Its usage is so prevalent that exFAT is the default file type on all SD cards larger than 32GB. With virtually no file size limit and a recommended maximum volume size of 512TB, the exFAT format is especially convenient and practical.

Limitations: exFAT possesses a few restrictions, and there are two major ones to consider. First, you can only use it on modern operating systems. Windows XP and Windows Vista require particular patch updates to use this format, and earlier versions cannot use exFAT at all. If your system runs an old operating system, the FAT32 format is recommended instead. As for macOS, your formatted pen drive will be incompatible with anything older than Mac OS X Snow Leopard. The second caveat is that the exFAT format has no journaling option. Journaling is a characteristic found in file types such as the FAT32 format and HFS+, which helps with recovery and data loss prevention if the USB key gets ejected during writing or formatting. So make sure that you properly eject your external flash drive when using this format to avoid compromising your data.

The FAT32 format

Description: Developed by Microsoft in 1996, the FAT32 format is the successor to FAT16. FAT32, while subpar in terms of efficiency when compared to more modern alternatives, possesses a significant advantage nonetheless. It is compatible across all possible operating systems, including old ones (such as anything pre-Windows XP, Mac OS X 10.5 Leopard or early Linux distributions). The FAT32 format is also the one you need to use if you intend on burning the disk image of Windows 10 on your pen drive. Indeed, you require a FAT32 format on your boot loader partition.

Limitations: The biggest drawback of this filetype is its file size limit of 4GB and, to a lesser extent, its maximum volume size of 2TB. So unless you specifically need to use a FAT32 format (see above), use the exFAT file type instead.

The NTFS format

Description: Whereas exFAT is often the recommended format for flash drives, NTFS is the format used for internal drives intended for a Windows pc. Created in 1993, NTFS is the standard implementation for Windows internal drives which replaced the FAT32 format as the standard for these drives. It comes with a journaling option by default and has virtually no file nor volume maximum size. The journaling allows for the prevention of data loss if somehow, the internal drive gets disconnected or abruptly moved during the writing or formatting process. 

Limitations: Whereas NTFS is readable and writable from any Windows operating system, macOS can only read it. As for Linux, exFAT can be read and written but only using an open-source NTFS driver (look for a package called NTFS-3G).

The ReFS format

Description: ReFS, aka Resilient File System, is a new format created by Microsoft which was built using NTFS as a foundation. Its intended use is for the Windows Server 2012 operating system. As such, it is not amongst the typical USB format types, and its primary purpose is for servers rather than computers. Because of its specific characteristics, it is not recommended to use this format on pen drives. With its automatic integrity checking, protection against data degradation and built-in management of redundancy and hard disk failure, ReFS is a self-repairing format with continual reliability.

Limitations: Whereas the FAT32 format and NTFS format can be made bootable by default, as of now, ReFS has no booting option. Consequently, you cannot use this file type for personal operating systems intended for at-home usage. Indeed, with this format, the OS will not be able to boot.

The HFS+ format

Description: HFS+, a proprietary file format created by Apple, is referred to using a different name on macOS: either Mac OS Extended (Journaled) or Mac OS Extended (Case-sensitive, Journaled). By default, macOS will use HFS+ as the default amongst the possible USB format types. A replacement for HFS, HFS+ was released in 1998 on Mac OS 8.1; however, it has since been replaced by APFS as the standard format of internal drives with the release of macOS High Sierra in 2017. Nonetheless, even with the arrival of APFS, HFS+ is still the standard when it comes to formatting external flash drives meant for macOS. With no maximum file size or volume size requirements, HFS+ is an excellent format for drives whose intended use is limited to Mac computers.

Mac OS Extended (Journaled): The “journaling” refers to a technique that helps protect your pen drive’s integrity by preventing disk inconsistency. Moreover, it proactively does disk repair in case an error occurs during formatting (such as not ejecting the disk properly). ****

Mac OS Extended (Case-sensitive, Journaled): Similar to the previous file type; the only difference between these two formats is the presence of case sensitivity. This option is only useful if you plan on having two or more files within the same directory that will have the same name but different capitalization. With the “Mac OS Extended (Case-sensitive, Journaled)” option you can, for example, have “MyFile.txt” and “myfile.txt” within the same folder. With the “Mac OS Extended (Journaled)” option, you cannot do that as both “MyFile.txt” and “myfile.txt” will be seen as the same file; you would need to either rename one or move a file to a different folder.

LimitationsIf you plan on using your pen drive on a computer running Windows 10, do NOT choose this file type. Indeed, Windows won’t be able to read or write the content of your external flash drive. This limitation does not apply to Linux, whose kernel includes the hfsplus module which allows for mounting, reading, and writing of HFS+ formatted drives. In the end, only choose HFS+ if you are sure that you will not use your USB stick on a Windows pc.

The APFS format

Description: APFS (which stands for Apple File System) is a proprietary Apple file system that the company released in 2017 alongside macOS High Sierra. They created this format as an eventual replacement to HFS+ (Mac OS Extended), both for internal SSD storage and flash drives. As of August 2019 however, macOS Mojave version 10.14.6 does not offer APFS as part of its possible formats when erasing an external pen drive using Disk Utility. As the automatic default format used for hard drives since macOS Mojave, the primary use of APFS is for internal disks rather than external USB keys.

Limitations: macOS automatically converts all internal devices with flash storage to APFS since High Sierra. Unfortunately, it isn’t possible to opt-out of this file type upon plugging a hard disk drive or other flash hard drives for the first time. As such, your formatted device will not be readable on previous macOS versions. Furthermore, just as with HFS+, any device formatted using this file type will not be readable on computers running Windows.

The ext2 format

Description: ext2 (second extended file system) was introduced in 1993, and is a file format designed for the Linux kernel. Even though devs have already released ext3 and ext4, there is still value in opting for ext2. Indeed, the fact that it lacks a journaling file system makes ext2 a potentially interesting choice for SD cards and older pen drives, as journaling usually decreases performance.

Limitations: Journaling (a technique that helps prevent disk inconsistency and proactively doing disk repair) is usually something you want when choosing a format. As ext2 lacks a journaling component, you might want to consider opting for ext3 or ext4 if you are using your pen drive to store sensitive data. Furthermore, as Linux is the intended operating system of ext2, it also lacks out-of-the-box compatibility with Windows and Mac. However, you can circumvent this with the use of an IFS (installable file system), a filesystem that allows the host OS to recognize and load drivers for different formats (including ext2).

The ext3 format

Description: With the arrival of Linux 2.4.15, 2001 saw the release of the successor to the ext2 format, ext3 (third extended file system). With its journaling, ext3 improves reliability and reduces the risks of corruption and data loss after you improperly eject a disk. Another advantage of ext3 is that it allows users to upgrade their ext2 formatted devices without the need to do a backup and restore.

Limitations: Overall, ext3 can be considered an in-between format whose main selling point is its backward-compatibility with ext2. Its characteristics are as such closer to ext2 (except for journaling) than to other contemporary file systems, and thus it lacks the performance one expects to find in modern formats. Because of this, it might be better to use its successor ext4 instead (unless you intend on upgrading devices already formatted using ext2). Finally, ext3 lacks out-of-the-box compatibility with Windows, and can only be read and written on macOS using the Paragon ExtFS software. On Windows, ext3 formatted devices can be read and written using an IFS (installable file system). This file system allows the host OS to recognize and load drivers for different formats (including ext3).

The ext4 format

Description: Ext4 (fourth extended filesystem) had its official stable release in 2008 and is the successor to the ext3 file system. Ext4 is one of the best format types for those looking to format their USB stick using a Linux-oriented file system. Indeed, it has backward-compatibility with ext3 and ext2, journaling, the capacity to support large files (16TB), and allows an unlimited number of subdirectories. 

Limitations: The main drawback of using ext4 as opposed to ext3 or ext2 is its lack of compatibility support on non-Linux operating systems. This format only has full read-write compatibility on macOS through the use of the Paragon EXTFS software. As for Windows, it is possible to view and copy files (but not to write) using the Ext2Read software. In both cases, there are no open-source options that offer cross-OS compatibility without having to tinker with some of the ext4 advanced features manually.

The XFS format

Description: Ported to the Linux Kernel in 2001, XFS is a 64-bit file system that is currently supported by most Linux distributions. With its limitless file and volume sizeXFS is an excellent choice for those wishing to use their external flash drives for large files or to deploy multiple storage devices at the same time. However, its use is aimed more towards storage servers and specific high-scale computing needs. As such, it is uncommon to find it as part of your typical USB format types. XFS is the default file system of some Linux distributions and notably the format used by the NASA Advanced Supercomputing Division.

LimitationsThis format is only compatible with the Linux operating system, which means that it cannot be written nor read on Windows or macOS. The XFS format is more niche than other file systems. Consequently, it is better suited for those having a specific computing goal in mind when opting for this format.

Owner and content creator behind ITgirl.tech. Geeky girl and blogger based in Montreal, Canada. Chocolate and nature lover (in that order). View all posts by Larryssa →

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