Format a USB Drive: FAT32, exFAT or NTFS?

You are formatting a USB stick and Windows offers three file systems with no explanation attached to any of them. The choice matters and it is not close.

One of the three cannot hold a single file over four gigabytes. That number decides it for most people, and no need to weigh anything else first.

I read what my own machine uses internally, and it turns out to be using two of the three at once.

The one number that decides it

Everything else is detail. This one decides it for you.

Documented by Microsoft in its file system comparison, the maximum file size on FAT32 is "4 GiB".

For NTFS and exFAT the table gives 2 to the power of 64 minus one byte, which is a number nobody will ever reach.

⛔ So your 5 GB video will not copy to a FAT32 stick. Not because the stick is full, and the error message rarely tells you which it is.

⭐ That single limit is why exFAT exists. It removed the ceiling without adding the parts of NTFS that a memory stick does not need.

What else the table says

Worth knowing, because the differences will affect you rather than being marketing.

Microsoft states in the same table that NTFS gets access control lists, file system level encryption and built-in compression. exFAT and FAT32 have none of the three.

And NTFS gets journaling. "Metadata-only journaling: Yes" for NTFS, "No" for both of the others.

⭐ Journaling is why NTFS survives a bad unplug better. It keeps a record of what it was in the middle of doing.

⚠️ NTFS also carries permissions, which is exactly what makes your stick refuse to open on somebody else's machine.

Ours: your PC is already using two of them

The check that makes this concrete, and it takes five seconds.

Ours, and counted on the internal drive here. Three volumes are NTFS and one is FAT32, on a single modern SSD.

⭐ The FAT32 one is the EFI System partition, which is how the machine boots. FAT32 is not obsolete, it is just wrong for a big file.

⚡ List yours the same way. It writes nothing:

Get-Volume | Select-Object DriveLetter, FileSystemType, DriveType

⚠️ No removable drive was attached when this was run, so the reading covers the internal disk only. Plug a stick in and it appears in the same list.

How to format one

Short. The dialog is simpler than it looks.

Right-click the drive in File Explorer, choose Format, pick the file system, and leave the label as something you will recognize.

⭐ Leave Quick Format ticked. Unticking it checks every sector and takes hours on a large drive, for a benefit you almost never need.

⚠️ Untick it only when you suspect the drive itself is failing. A full format finds bad sectors and marks them, which a quick one does not.

⚡ If the drive is not listed at all, there is a longer list of reasons and Disk Management is step one.

Which to pick, by what the stick is for

The practical answer. Four lines.

⭐ exFAT for anything you move between machines. No file size ceiling, and Windows, macOS and most televisions read it.

⭐ NTFS for a drive that stays on one Windows PC, especially a backup disk. Permissions, journaling and compression all earn their place there.

⚡ FAT32 only when something demands it. Car stereos, older cameras, some game consoles and certain BIOS updates.

⛔ Ours: if you do not know which the device wants, try exFAT first. FAT32 is the fallback, not the default.

What formatting does and does not erase

Being clear, because people lose things at exactly this point.

⛔ Formatting removes the index, not the contents. The files are still physically there until something writes over them, which is why recovery tools work at all.

⚠️ So a quick format is not secure erasure. For a drive you are selling or throwing away, that distinction matters.

⭐ And it does not repair a failing drive. I have watched people reformat the same stick three times. It keeps corrupting files on a fresh file system.

Allocation unit size, and why to ignore it

One line, because the dialog asks you and nobody knows the answer.

⭐ Leave it on Default. Windows picks a sensible cluster size for your drive and your file system.

⚡ Larger clusters waste space on small files and gain almost nothing otherwise. It is a setting for people with a specific reason.

⚠️ Microsoft ties NTFS volume limits to it, listing "16 TB (4 KB Cluster Size) or 256TB (64 KB Cluster Size)". That is the only place it genuinely matters.

When Windows refuses to format it

Practical, and three causes cover nearly everything you will hit.

⛔ Write protection. A physical switch on the stick, or a flag set on the drive. The dialog says access denied and nothing else.

⚠️ Something has the drive open. Close File Explorer windows pointing at it and try again before anything more drastic.

⚡ And if Windows will not even see it to format, that is a recognition problem rather than a formatting one.

⭐ Ours: Disk Management shows drives File Explorer hides, and formatting from there works when the right-click route does not.

Status: read against Microsoft's published file system comparison 25 August 2026. The 4 GiB maximum file size on FAT32, the 2^64 minus 1 byte figure for NTFS and exFAT, the NTFS volume limits by cluster size, and the presence or absence of access control lists, encryption, compression and journaling are all from that table. The volume file systems were counted on the internal drive here.

What file system should I use for a USB drive?

exFAT for anything you move between machines, because it has no practical file size limit and Windows, macOS and most televisions read it. NTFS for a drive staying on one Windows PC. FAT32 only when a device specifically asks for it.

Why will a 5 GB file not copy to my USB stick?

Because your stick is formatted FAT32, and Microsoft gives the maximum file size on FAT32 as 4 GiB. It is not full. Reformat it as exFAT and the same file copies without complaint.

Is Quick Format enough?

For almost everything, yes. Unticking it checks every sector and takes hours of your time, which is only worth it if you suspect the drive itself is failing. Neither option is a secure erase.

Does formatting a drive delete the files permanently?

No. Formatting removes the index rather than the contents, which is why recovery tools can often get files back. For a drive you are selling or discarding, that is not enough.

Why does my USB drive show less space than it says on the box?

Part of it is the file system taking a share, and part is that manufacturers count a gigabyte as a thousand million bytes while Windows counts it in binary. So a 64 GB stick showing you about 58 GB is normal.

The Short Version

• Microsoft gives the FAT32 maximum file size as 4 GiB. That decides it for most people.
• NTFS and exFAT both allow file sizes nobody will reach.
• NTFS alone gets access control lists, encryption, compression and journaling.
• Those permissions are also why an NTFS stick can refuse to open elsewhere.
• The machine here runs three NTFS volumes and one FAT32, which is the EFI partition.
• exFAT for moving between machines, NTFS for a Windows-only drive, FAT32 on request.
• Leave Quick Format and Default allocation size alone unless you have a reason.
• Formatting removes the index, not the contents. It is not a secure erase.

Where to Next

Check what your stick is formatted as before you copy anything large to it. One command lists every volume and its file system.

If it says FAT32 and you move video files, reformat it as exFAT. That one change removes the only limit you are likely to hit.

Leave Quick Format ticked and the allocation size on Default. Both defaults are right for almost every drive.

Before formatting anything, check the drive is genuinely unreadable rather than simply unlettered. Those two look identical from File Explorer and only one is destructive to fix.

And if you have a device that still insists on FAT32 in 2026, tell me what it is in the comments. That list is shorter every year and worth keeping.