To see what file format your USB flash drive uses in Windows, open File Explorer, select This PC, right-click the drive, choose Properties, and read the File system line. It usually says FAT32, exFAT or NTFS. On a Mac, select the drive in Finder and press Command-I, then read the Format line.
The “format” of a flash drive is its file system: the method the drive uses to organize files so a computer can find them. It matters when a TV, game console, camera or Mac won’t read the drive, or when a large file refuses to copy. Checking the format is read-only. Nothing below changes or erases the drive unless you deliberately reformat it.
These steps apply to Windows 11 and Windows 10, and to current versions of macOS. The details come from Microsoft and Apple documentation.
How to Check a USB Drive’s Format in Windows
This is the shortest route, and it doesn’t need an administrator account.
- Plug the USB flash drive into your computer and wait a few seconds for Windows to recognize it.
- Open File Explorer. Pressing Windows key + E opens it from anywhere.
- Select This PC in the left pane. The flash drive appears with the other drives, with a letter such as D: or E:.
- Right-click the flash drive and choose Properties.
- On the General tab, read the File system line near the top.
- Select Cancel to close the window without changing anything.
You’ll see the format, such as FAT32, exFAT or NTFS, along with the drive’s used space, free space and capacity. If you don’t see the drive in This PC at all, start with how to open a USB drive on Windows 11.
How to See the Format in Disk Management
Disk Management is the Windows tool that, in Microsoft’s words, shows information about each drive on your computer and all the partitions on each drive. It helps when a flash drive has no drive letter, or when you want to compare several drives at once. A partition, also called a volume, is a section of a drive that Windows treats as its own drive.
- Right-click the Start button and select Disk Management. For other ways in, read about opening Disk Management in Windows 11.
- Find the flash drive in the volume list in the upper part of the window. Its size is the easiest way to pick it out.
- Read the File System column for that row.
Warning: Disk Management can also format drives and delete volumes, and both erase data. Only look. Close the window when you have your answer. Microsoft describes the tool in its Disk Management overview.
How to Check the Format From the Command Line
Two built-in commands report the file system. They’re handy if File Explorer won’t open, or if you want text you can copy.
Command Prompt
Microsoft’s fsutil fsinfo reference documents a command that lists a volume’s file system.
- Open the Start menu, type cmd, and open Command Prompt.
- Type
fsutil fsinfo volumeinfo E:, replacing E: with your flash drive’s letter, and press Enter. - Look for the File System Name line in the output.
The same output shows the volume name and serial number. If you aren’t sure of the drive letter, fsutil fsinfo drives lists every drive on the computer. If Windows reports that the command needs elevated rights, open Command Prompt with Run as administrator and try again.
If the flash drive keeps getting a confusing letter, you can change the drive letter in Windows 11 to one you will recognize.
PowerShell
Open Windows PowerShell or Terminal from the Start menu and type Get-Volume -DriveLetter E, again using your drive’s letter. Microsoft’s Get-Volume documentation shows a table that lists the file system beside the drive’s health status, remaining space and size. Typing Get-Volume alone lists every volume.
How to Check a USB Drive’s Format on a Mac
There are two places to look. Finder is quicker. Disk Utility gives more detail.
In Finder
- Plug in the flash drive and select it in a Finder window’s sidebar or on the desktop.
- Choose File > Get Info, or press Command-I.
- Read the Format line in the Info window that opens.
The same check appears in Apple’s article about saving files to an external drive.
In Disk Utility
- Open Disk Utility. It’s in the Utilities folder inside Applications, or you can search for it with Spotlight.
- Choose View > Show All Devices so the sidebar shows the drive and the volumes on it.
- Select the flash drive or its volume in the sidebar.
- Click the Info button in the toolbar for the full details.
The details can include the format being used, the total capacity, the available space and where the volume is mounted. You’ll see whether the drive uses APFS, Mac OS Extended, MS-DOS (FAT) or ExFAT. MS-DOS (FAT) is the name Disk Utility uses for FAT formats such as FAT32. More is in Apple’s Disk Utility guide.
Warning: the Erase button in Disk Utility reformats the drive and removes its files. You don’t need it to check the format.
What Each USB Format Means
The biggest practical difference is file size. According to Microsoft’s file system comparison, FAT32 can’t store a single file larger than 4 GiB, while NTFS and exFAT allow far larger files. A GiB is slightly bigger than the gigabyte printed on a drive’s packaging, so in everyday terms the limit is about 4 GB per file.
| Format | Largest single file | Good to know |
|---|---|---|
| FAT32 | 4 GiB | Shown as MS-DOS (FAT) in Disk Utility. Recommended for Windows volumes of 32 GB or less. |
| exFAT | Far beyond 4 GiB | A Windows-compatible format that Disk Utility can also create. Recommended for Windows volumes over 32 GB. |
| NTFS | Far beyond 4 GiB | Adds Windows features such as file permissions, compression and encryption. A Mac might read it but can’t write to it. |
| APFS or Mac OS Extended | Not covered here | Mac formats. APFS is the default on Macs using macOS 10.13 or later. |
The Disk Utility file system formats guide lists every format Disk Utility offers and when to use each. In short:
- FAT32 is the older format. Many devices with a USB port expect it, but the 4 GiB file limit rules out long, high-quality videos.
- exFAT removes that limit and is a Windows-compatible format a Mac can write to, so it suits a drive you move between a PC and a Mac.
- NTFS is the format Windows uses for its own drives. Disk Utility doesn’t support it, and a Mac might be able to read from it but not write to it.
- APFS and Mac OS Extended are Mac formats. Expect to use a flash drive in these formats only with Macs.
A TV, car stereo, console or streaming player may accept only some of these. Check that device’s manual or support page, since the supported list differs from one device to the next. If you have a Roku, here’s how to play videos from a USB drive on it.
Troubleshooting
- The drive doesn’t appear in This PC. Try another USB port, then look for it in Disk Management. The steps for fixing a USB drive that isn’t showing up in Windows 11 walk through the causes.
- There’s no Properties option when you right-click. Make sure you right-clicked the drive itself under This PC, not a file or folder inside it. You can also select the drive and press Alt + Enter.
- The file system is blank or says RAW. That generally means Windows can’t recognize a file system on the drive. The drive may be damaged, or it may use a format Windows doesn’t read, such as a Mac format. Don’t accept an offer to format it if you need the files. Try the drive on the computer that last used it.
- The drive shows more than one entry. A flash drive can hold more than one partition, and each one can have its own format. Check each entry separately.
- A file won’t copy even though there’s free space. If the drive is FAT32 and the file is larger than 4 GiB, the format is the cause, not the free space.
- You can open files on a Mac but can’t save to the drive. Check the format. NTFS is a format a Mac might read but not write.
Frequently Asked Questions
Does checking the format erase or change my flash drive?
No. Opening Properties, Disk Management, Get Info or Disk Utility only displays information. Data is erased only if you choose a command such as Format or Erase and confirm it.
How do I change my USB drive’s format?
You reformat it, which erases everything on it, so copy your files somewhere else first. On Windows 11, here’s how to format a USB drive to FAT32. After reformatting, repeat the steps above to confirm the new format. There is no undo: your earlier files return only when you copy them back from your backup.
Which format should a flash drive use for both Windows and Mac?
Apple calls MS-DOS (FAT) and ExFAT its Windows-compatible formats, and suggests MS-DOS (FAT) for volumes of 32 GB or less and ExFAT for larger ones. exFAT also avoids the 4 GiB file limit.
Why can’t I copy a large video to my flash drive?
The drive is probably FAT32, which can’t hold a single file larger than 4 GiB no matter how much space is free. Check the format with the steps above. A drive formatted as exFAT or NTFS doesn’t have that limit.
How do I wipe a USB drive completely?
Here’s how to delete everything on a USB flash drive. If the drive has been used in other computers and you have Norton installed, you can also scan the USB flash drive with Norton 360 before opening its files.
Can a USB drive have more than one partition?
Yes, and each volume can have its own format. To split a drive in Windows, here’s how to partition a hard drive on Windows 11.
What to Do Next
Once you know the format, compare it with what your other device supports. If they match, the format isn’t the problem. If they don’t, back up the drive, then reformat it to a format both devices accept.
When the drive is ready, here is how to put files on a flash drive in Windows.
Matthew Burleigh is the founder, head writer, and editor of Solve Your Tech, which he launched in 2012. He has written technology tutorials since 2008 and worked in IT since 2003, including small-business support, IT management, and consulting. He holds Bachelor’s and Master’s degrees in Computer Science from Arizona State University.
Matthew writes practical guides for Windows, iPhone and iPad, Microsoft Office, Outlook, Google apps, and Android. Solve Your Tech’s guides are checked step by step against the device or app maker’s own documentation and tested on his own devices whenever he has the hardware or software, with clear steps, sources, and update dates.
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