How do you check the format of a USB drive?

Quick Answer

There are a few simple ways to check the format of a USB drive on Windows and Mac computers. On Windows, you can check the file system by looking at the drive’s properties in File Explorer. On a Mac, you can use Disk Utility or Terminal to find the format. The most common formats for USB drives are FAT32 and exFAT. Knowing the format allows you to check for compatibility issues or determine if the drive needs to be reformatted.

Steps to Check Format on Windows

Here are the steps to check the format of a USB drive on a Windows PC:

1. Insert the USB drive into your computer.

2. Open File Explorer and locate the USB drive under “This PC” or “My Computer.” It will usually be labeled as the drive letter, like “E:”.

3. Right click on the drive and select “Properties.”

4. In the Properties window that opens, look at the “File system” field to see the format of the drive. Common options are FAT32, exFAT, or NTFS.

5. If the format says “RAW” that means the drive is unformatted and will need to be formatted before use.

6. To reformat a drive, right click it, select “Format…” and choose the desired file system.

This simple process allows you to quickly identify the format of any USB drive plugged into your Windows system. Knowing the format helps determine if the drive is compatible with different operating systems and devices.

Check Format on Mac

Checking the format of a USB drive on a Mac is also straightforward. Here are two options:

Use Disk Utility

1. Connect the USB drive to your Mac.

2. Open Disk Utility (located in Applications > Utilities).

3. Locate the USB drive in the left side panel and select it.

4. Look for the “Format” field to see the file system format.

5. If you need to reformat the drive, click “Erase” and select the new format.

Use Terminal

1. Connect the USB drive to your Mac

2. Open the Terminal app (located in Applications > Utilities).

3. Type “diskutil list” and press Return.

4. Locate the USB drive identifier code in the volumes list (this will start with external, followed by the size)

5. Type “diskutil info diskX” replacing X with the disk number of the USB drive.

6. Look for the “File System Personality” field in the disk info printout.

Both Disk Utility and Terminal provide easy ways to identify and confirm the file system format of a USB drive on a Mac. This allows you to check for compatibility or reformat the drive if needed.

Most Common USB Drive Formats

There are a few common file system formats used for USB flash drives today:


FAT32 is the oldest and most compatible format. It can be read and written to by all operating systems including Windows, Mac, Linux, game consoles, media players, and more. However, it has a maximum file size limit of 4GB and inefficient storage compared to newer formats.


exFAT is a newer generation of FAT32 without the file size limits. It supports files over 4GB and efficient storage. The tradeoff is that exFAT is not quite as universally compatible, but most modern devices can read and write it.


NTFS is the standard Windows file system. It is efficient and robust against corruption. But it is primarily limited to Windows PCs, some gaming devices, and Linux with additional software. Mac and other operating systems will be able to read NTFS drives but not write to them.


HFS+ is the Mac file system. Similarly to NTFS, it has good performance and runs natively on Macs, but with limited compatibility elsewhere. HFS+ drives can be read by Windows but not written to without third party software.

In most cases, FAT32 or exFAT are the best choices for USB drive file systems due to their balance of compatibility and capabilities. Unless you specifically need a capability of NTFS or HFS+ for a particular device, standard flash drives will work well formatted with FAT32 or exFAT.

Reformatting a USB Drive

If your USB drive is formatted with an incompatible file system for your computer, or you want to change it for other reasons, you can easily reformat the drive. Here is how to do this on Windows and Mac:

On Windows:

1. Insert the USB drive into your computer.

2. Open File Explorer, right click on the drive, and select “Format…”

3. In the Format window, under File System, select the desired file format.

4. Check “Quick Format” to format faster, unless you need a full format to wipe the drive.

5. Click “Start” to begin reformatting the drive.

On Mac:

1. Insert the USB drive into your computer.

2. Open Disk Utility.

3. Select the drive in the left side panel.

4. Click “Erase” along the top menu.

5. Select the desired format from the drop down.

6. Rename the drive if desired.

7. Click “Erase” to reformat the drive.

Reformatting the drive will wipe all data, so be sure to back up your files first if you need to preserve anything on the drive. After reformatting, the USB drive will be ready to use with the new file system.

Checking Format Before Purchasing

When purchasing a new USB flash drive, you may want to check what file system it is preformatted with before buying. This can save you an extra reformatting step if you need the drive to work with a certain operating system.

Here are some tips for checking format before purchasing:

– Look at the packaging – some USB drives will indicate the format, such as “Compatible with Mac” or “NTFS/HPF+”

– Ask the retailer if they know the format, especially for store brand drives

– Search online – find the brand and model number and see if you can find details on the default format

– Read customer reviews – previous buyers will often mention if a drive had to be reformatted

– Buy from major brands – large manufacturers like SanDisk and Kingston are more likely to use standard formats like FAT32 or exFAT

– Be prepared to reformat – when in doubt, assume you may need to reformat, so don’t store critical data before checking the format first

While most USB drives today will be widely compatible, checking the format in advance can avoid headaches later if you get a rarer format like NTFS or HFS+ and need it to work across platforms. Knowing the format in advance or being prepared to reformat saves time and effort.


Checking the file system format of a USB drive is easy on both Windows and Mac computers. This allows you to identify compatibility issues, troubleshoot formatting problems, and reformat the drive if needed to a standard file system like FAT32 or exFAT that works across all devices. Formatting in advance or being willing to reformat after purchase ensures your USB drive will work right away with the platforms and devices you need. With the simple steps provided, you can now seamlessly check and manage the format of any USB drive.

Operating System Check Format Steps
Windows 1. Insert drive 2. Open File Explorer 3. Right click drive, select Properties 4. View File System field
Mac 1. Insert drive 2. Open Disk Utility 3. Select drive 4. View Format field
Mac Terminal 1. Insert drive 2. Open Terminal 3. Type diskutil list 4. Locate drive identifier 5. Type diskutil info diskX 6. View File System Personality field