Type a meaningful description in the Name field (I usually avoid using special symbols, underscores, and spaces). You need to provide three pieces of information: Name, Format, and Size. Since this is a brand new drive, it won’t have partitions like this:Ĭlick on the Partition button in the top toolbar of the app. On the left side of the app, locate the flash drive. This will open the Disk Utility app.Īnother way to open the app is to use the Spotlight Search: press simultaneously Command and Space bar keys and type “Disk Utility” in the search bar. If the drive was never used before (and does not contain any valuable data), then click on the Initialize button. If the USB drive was not formatted, then the first time you plug it into the Mac, you will see the error message “The disk you inserted was not readable by this computer” with the options to Initialize, Ignore and Reject. In some cases, the drives were not formatted at all. Most flash drives that you can purchase are preformatted in the Windows format (because there are more PC users than Mac users). The drive that has been used in Windows or another operating system.

It is possible that the drive was not formatted in a disk format compatible with macOS. There are two special cases when a USB drive may not be accessible, but not because it was corrupted. How To Fix Unreadable USB Flash Drive On Mac Verify the USB drive was formatted for compatibility with macOS However, before fixing the problem, check if the drive was correctly formatted. After selecting the drive in the Disk Utility, click on the First Aid button to verify the device. MacOS has a built-in tool that can help fix an unreadable USB flash drive on Mac: Disk Utility. If the USB flash drive appears to be corrupted, e.g., when Mac cannot detect it or refuses to mount the drive, make sure that it was properly prepared. However, more often than not, the problem is not with the device itself, but how we use them. They can be damaged or have data corrupted. And every once in a while, this transfer method fails because flash drives are physical devices. Flash, or thumb, drives are a great way to transfer data between multiple computers.

Usb flash drive mac