#Usb drive won't read formatted for mac how to#
#Usb drive won't read formatted for mac mac os#
#Usb drive won't read formatted for mac Pc#
#Usb drive won't read formatted for mac mac#

One issue that beginner users often face is when the USB drive won’t mount on Mac.

#Usb drive won't read formatted for mac mac#

Unfortunately, if the drive was already formatted with NFTS, the only way to reformat for read/write Mac compatibility is first to save the contents of the drive on another computer or disk, reformat to ExFAT, and then copy the files back to drive. Macs cannot delete or modify the file contents on NTFS drives. Macs can also read from drives formatted as NTFS, but only in read-only mode. In other words, if the file is formatted as MS-DOS device, you will not be able to copy files larger than 4 GB on it. The problem with MS-DOS format is that it was intended to store files less than 4GB. macOS fully supports FAT32 (appears as MS-DOS in the Disk Utility) and ExFAT.

#Usb drive won't read formatted for mac Pc#

Here is a file format compatibility table from my previous post: FormatĪs you can see from the table above, Macs support most PC formats, while PC only supports its own ones. In case there is a possibility, even a remote one, that the flash drive will be used with Windows computers, then pick ExFAT.

However, do not use case-sensitive variants: I don’t know a single case when it could be useful. If you need encryption, then use the encrypted version of the format.

#Usb drive won't read formatted for mac mac os#

If you are absolutely sure that the flash drive will only be used with Mac computers, and there will never be a need to copy something to and from PC, then the best format is Mac OS Extended Journaled. When it comes to the format, there are many choices, and the choice depends on how the flash drive is going to be used. 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.

#Usb drive won't read formatted for mac how to#

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.