ExFAT - The Forgotten File Format

Although I would love to only use Mac OS X, unfortunately my job requires me to constantly switch to a Windows machine. To help make this process less painful, I use tools such as Dropbox to ensure my data is always synchronised. However Dropbox is not practical for every situation, therefore at times I still need to use an external USB drive to copy large quantities of data between the two platforms. The main challenge when doing this is selecting a file format that both Mac OS X and Windows can read and write to. For example, Windows can obviously read and write to NTFS, but the Mac (without third party help) can only read, while Windows can't even read the Mac standard HFS+. So what are the other options?

The most obvious option is FAT32, which is an old format originally introduced with Windows 95 OSR2. FAT32 is fully compatible with Windows and Mac, but has one significant limitation, which is a 4GB file size limit. That would have been fine a few years ago, but now I regularly copy files larger then 4GB. So that leaves the lesser known ExFAT.

ExFAT is a replacement for FAT32 and was designed with external storage in mind. It is compatible with both Windows and Mac and does not have the 4GB file size limit. It can also be created (formatted) on both a Mac and Windows system, for example using Disk Utility on the Mac (as shown in the image below).

The one downside with ExFAT is that it is not as widely supported as FAT32, but thankfully the main operating systems are covered:

• Windows Embedded CE 6.0
• Windows XP (including x64) SP2 & later
• Windows Vista SP1 & later
• Windows 7
• Windows 8
• Windows Server 2003 requires SP2
• Windows Server 2008
• Windows Server 2008 R2
• Windows Server 8
• Mac OS X 10.6.5 & Later

So my recommendation for anyone requiring easy access between Mac and Windows is to have an ExFAT formatted USB Drive ready and waiting. I promise this will save you a lot of headaches.