What format is my USB drive?
Most USB drives today use FAT32 or exFAT formats; some drives may be NTFS or APFS depending on their intended use. To know for sure, inspect the drive with your computer’s tools. The format affects compatibility, file-size limits, and how your data can be accessed on different devices.
Common USB file systems you’ll encounter
Here is a quick guide to the formats you’re likely to see and what they mean for cross‑device use.
At a glance
- FAT32 — broad compatibility across old and new devices. Supports small drives and millions of devices, but enforces a 4 GB maximum file size and has limited metadata capabilities.
- exFAT — modern replacement for FAT32. No practical 4 GB file limit and supports large volumes. Widely supported on Windows, macOS, and newer Linux distributions; some older Linux setups may require extra packages.
- NTFS — Windows’ default for internal drives and many USB sticks used with PCs. Supports large files and permissions, but macOS typically offers read-only access by default and Linux requires extra drivers for full write support.
- APFS — Apple’s current file system for Macs. Excellent performance on Apple hardware but not natively supported on Windows; Linux support is limited.
- ext4 — Linux’ native format. Very reliable for Linux use, but not readily readable on Windows/macOS without special software.
In practice, exFAT is the go-to choice for cross‑platform USB drives, while FAT32 remains useful for very old devices. NTFS is common for Windows-centric workflows, and APFS/ext4 are best suited to Apple- or Linux‑only environments.
How to check the format on Windows
Use File Explorer or Disk Management to verify the drive’s file system.
- Open File Explorer and locate the USB drive under “This PC.”
- Right-click the drive and select “Properties.”
- Look at the “File system” line to see FAT32, NTFS, or exFAT.
- Optional: Open Disk Management (Win+X, then Disk Management) and read the “File System” column for the USB drive.
Knowing the file system helps you decide whether you need to reformat for cross‑platform use or keep it as is for Windows‑only use.
How to check the format on macOS
Disk Utility and Get Info reveal the drive’s format.
- Open Disk Utility (Applications > Utilities > Disk Utility).
- Select the USB drive in the left sidebar (choose the top-level device, not the indented volume).
- Look at the “Format” field in the right pane, or press Command-I to open Get Info and see the format there.
- Ensure you’re viewing the correct drive if multiple drives are connected.
The displayed format tells you how macOS will handle the drive and whether cross‑platform usage is straightforward.
How to check the format on Linux
Linux offers both terminal commands and GUI tools to identify a USB drive’s file system.
- Plug in the USB drive and identify it (for example, /dev/sdb1) using lsblk -f or blkid.
- Read the FSTYPE column in the output (e.g., vfat for FAT32, exfat, ntfs, ext4).
- Install and use exfatprogs or ntfs-3g if you need to access exFAT or NTFS and your distribution lacks native support.
- Optionally, mount the drive and inspect its contents to confirm you’re looking at the correct device.
Linux offers robust support for many formats, but you may need additional packages to handle exFAT or NTFS depending on your distro.
Summary
To determine your USB drive’s format, use the built‑in tools of your operating system—Windows, macOS, or Linux—to view the file system. For broad cross‑platform use, exFAT is usually the best default; FAT32 works for very old or limited devices; NTFS is Windows‑friendly for large files, while APFS or ext4 are best when the drive is confined to Apple or Linux ecosystems. Always back up data before reformatting to avoid data loss.
