How to Format a USB Drive on Windows and Mac
Formatting a USB drive erases everything on it, so copy off anything you need first. After that the whole job takes under a minute on both Windows and Mac. The only real decision is the file system, and for most people the answer is exFAT.
Pick the file system first
The file system controls which devices can read the drive. exFAT works on Windows, Mac, most TVs, and car stereos, and it accepts files larger than 4 GB. FAT32 is the older standard that works almost everywhere but caps single files at 4 GB. NTFS is Windows-only in practice, and APFS is Mac-only.
- exFAT for a drive you move between Windows, Mac, TVs, and cars
- FAT32 for devices that reject exFAT, usually older car stereos or consoles
- NTFS only for drives that stay on Windows
- APFS only for drives that stay on Mac
Formatting on Windows
Plug in the drive, open File Explorer, right-click the drive, and choose Format. Pick exFAT from the file system menu, leave the allocation unit size on default, and click Start. On a drive under 128 GB the quick format finishes in a few seconds.
Formatting on Mac
Plug in the drive, open Disk Utility from Applications, then Utilities, select the drive entry under the External heading, and click Erase. Choose exFAT for the format and GUID Partition Map for the scheme, then click Erase. If a drive keeps failing to format or reverts to read-only, it is likely dying, so copy off what you can and replace it.
