exFAT can be used where the NTFS file system is not a feasible solution (due to data structure overhead), or where the file size limit of the standard FAT32 file system (that is, without FAT32+ extension) is unacceptable.
For the typical user, seamless interoperability between Windows and OS X platforms for files in excess of 4 GiB. NOTE: Windows XP may require Update for Windows XP (KB955704) to manage exFAT formatted drives.
Scalability to large disk sizes: 64 ZiB[nb 2] theoretical max, 512 TiB recommended max, raised from the 32-bit limit (2 TiB for sector size 512) of FAT32 partitions.
File size limit of 16 EiB–1 byte.[nb 1] (limited by volume size), raised from 4 GiB−1 byte in a standard FAT32 filesystem. (The open FAT32+ specification proposes an extension how to store files up to 256 GB on otherwise backward-compatible FAT32 volumes as well. This extension is available in some versions of DR-DOS so far, but is trivial to implement in other FAT32 implementations as well.)
Optional support for TexFAT, a transactional file system standard (optionally WinCE activated function).
Provision for OEM-definable parameters to customize the file system for specific device characteristics.
The disadvantages compared to FAT file systems include:
Microsoft has not released the official exFAT file system specification[contradiction] , and a restrictive license from Microsoft is required in order to make and distribute exFAT implementations. Microsoft also asserts patents on exFAT which make it impossible to re-implement its functionality in a compatible way without violating a large percentage of them. This renders the implementation, distribution, and use of exFAT as a part of free or open-source operating systems or of commercial software, for which the vendors could not obtain a license from Microsoft, legally difficult, especially in countries that recognize United States software patents.
Limited support outside Windows and Mac OS X operating systems as of 2012[update], when most consumer electronic devices could only handle FAT12/FAT16/FAT32, rendering exFAT (and flash memory formats using it) impractical as a universal exchange format.
Some distributions of Linux have begun to include support for exFAT. It is however, only available as a file system in user space, as it is not supported by the kernel.
All Windows NT versions starting with Windows XP support exFAT.  Updates may be required before use.
The standard exFAT implementation is not journaled and only uses a single file allocation table and free space map. FAT file systems instead used alternating tables, as this allowed recovery of the file system if the media was ejected during a write (which occurs frequently in practice with removable media). The optional TexFAT component adds support for additional backup tables and maps, but may not be supported.
Support for up to 2,796,202 files per subdirectory only.[nb 3] Microsoft documents a limit of 65,534 files per sub-directory for their FAT32 implementation, but other operating systems have no special limit for the number of files in a FAT32 directory. FAT32 implementations in other operating systems allow an unlimited number of files up to the number of available clusters (that is, up to 268,304,373 files on volumes without long filenames).[nb 4]
Support on other platforms
A FUSE-based implementation named fuse-exfat, or exfat-fuse, with read/write support is available for FreeBSD and multiple Linux distributions. None of the solutions can become an official part of Linux due to the patent encumbered status of the exFAT filesystem. A non-FUSE implementation has also been released, written by Samsung. It was initially released on GitHub unintentionally, and later released officially by Samsung in compliance with the GPL.
Proprietary read/write solutions licensed and derived from the Microsoft exFAT implementation are available for Android, Linux, and other operating systems from Paragon Software Group and Tuxera.
XCFiles (from Datalight) is a proprietary, full-featured implementation, intended to be portable to 32-bit systems. Rtfs (from EBS Embedded Software) is a full-featured implementation for embedded devices.
Two experimental, unofficial solutions are available for DOS. The loadable USBEXFAT driver requires Panasonic's USB stack for DOS and only works with USB storage devices; the open-source EXFAT executable is an exFAT filesystem reader, and requires the HX DOS extender to work. There are no native exFAT real-mode DOS drivers, which would allow usage of, or booting from exFAT volumes.
Companies can integrate exFAT into a specific group of consumer devices, including cameras, camcorders, and digital photo frames for a flat fee. Mobile phones, PCs, and networks have a different volume pricing model.
^ abAlthough Microsoft published a different value in KB955704, the file size is in bytes and is stored as a 64 bit number. The largest theoretical file size would be 16 EiB−1 byte, the same as NTFS. However, since the true theoretical maximum volume size under the current specification cannot exceed 128 PiB, a file can never reach that file length.
^This value was calculated based on the 64-bit value of number of sectors with a sector size of 4096 bytes. However, based on the current exFAT specification the FAT is 32 bits and the largest cluster is 25 bits resulting in a maximum addressable volume size of close to 128 PiB
^This limit only applies to subdirectories because the maximum subdirectory is 256 MiB. There is no limit for the root directory
^268,304,373 files = 2^28 - 11 reserved clusters - 131,072, the minimum number of 64 KB clusters occupied for the 268,435,445 directory entries (á 32 bytes) without VFAT LFNs, which are required for 268,435,445 files with sizes between 1 and 65535 bytes. With VFATs, the 131,072 number must be multiplied by 21 (worst case), which would result in 265,682,933 files instead.