How to Format a Flash Drive on Mac
Formatting a USB drive on Mac before you start using it clears any data stored on the drive and makes sure it’s set up with a file system that your Mac is designed to use. To format a USB flash drive to work with your Mac, follow these instructions:
How to Format a USB Drive on Mac With Multiple Partitions
When you format a USB drive that has multiple partitions, you will find that only one partition is formatted. The other partitions will remain exactly as they were before, including their original file system and whatever files are stored there. If you want to format your USB drive such that it has a single partition that’s formatted for use with your Mac, follow these instructions:
Why It’s Necessary to Format USB Drives for Macs
Mac and Windows computers use different file systems, only some of which are cross-compatible. In computing, it’s easy to think of a file system as the system that a computer uses to store, identify, and retrieve files. Without a file system, a computer wouldn’t be able to store new files, and stored files would be impossible to retrieve. When you buy a new USB flash drive, SD card, hard drive, or any storage media, there’s a good chance that it either isn’t formatted or that it was formatted at the factory for use with Windows computers. Some of these devices will still work with your Mac out of the box, but you’re better off formatting the drive yourself to use a Mac-specific file system like Mac OS Extended (Journaled) or a format that works across platforms like ExFat.
