How to convert an NTFS drive to exFAT on Mac without losing data

Why there is no in-place conversion

NTFS and exFAT store their file tables and allocation data in completely different layouts. Windows can convert FAT32 to NTFS in place, but nothing equivalent exists for NTFS to exFAT on macOS. Any tool that claims to do so has to move or rewrite every file, and a power cut or bad sector in the middle can destroy the only copy. A full backup first is not optional.

Before you start

• Space: you need a backup location with at least as much free space as the data on the drive (used space, not total capacity). Run Get Info on the drive in Finder to see how much is used.
• Backup destination: another external drive or your Mac's internal disk formatted as APFS, Mac OS Extended or exFAT. Not FAT32 (4 GB file limit) and not an NTFS drive that macOS can only read.
• Drive type: this method does not apply to a Windows system or boot drive, a Boot Camp partition, or a BitLocker-encrypted drive. Decrypt BitLocker in Windows first.
• Power and cable: use a stable cable, plug a laptop into power, and do not let the Mac sleep during copies. Large drives take hours.

Method 1: Disk Utility (no command line)

Do this only after your files are copied to the backup and checked (see the backup section below).

1. Open Disk Utility (Applications > Utilities). In the View menu choose Show All Devices.
2. In the sidebar select the physical drive itself (the top-level entry with the manufacturer name), not just the NTFS volume under it.
3. Click Erase. Name the volume, set Format to ExFAT and Scheme to GUID Partition Map. Choose Master Boot Record only if an old camera, TV or car stereo requires it.
4. Double-check that the selected device is the right one, then click Erase and wait for it to finish.
5. When it is done the drive appears as an exFAT volume. Copy your files back from the backup, then verify them.

Method 2: Terminal with diskutil

List external disks, identify the right identifier carefully (for example /dev/disk4), then erase it. Replace MYDRIVE with the volume name and disk4 with your own identifier.

# find the identifier of your external disk (look at SIZE and NAME)
diskutil list external

# ERASES the whole disk: format it as exFAT with a GUID partition map
diskutil eraseDisk ExFAT MYDRIVE GPT /dev/disk4

diskutil eraseDisk destroys everything on the disk you give it. If you pick the wrong identifier, for example your internal disk, there is no undo. Check diskutil list external output twice.

Backing up and verifying (do not skip this)

Step 1: copy the files to your backup location. This rsync command copies recursively, keeps modification times, and skips Windows system folders. Note the trailing slashes.

rsync -rtv --progress \
  --exclude='System Volume Information' --exclude='$RECYCLE.BIN' \
  /Volumes/OLDDRIVE/ /Volumes/BACKUP/OLDDRIVE-backup/

Step 2: compare the file count and total size on the original and the backup. They should match (apart from the skipped system folders).

find /Volumes/OLDDRIVE -type f | wc -l
du -sk /Volumes/OLDDRIVE

Step 3: a byte-for-byte check. This dry run with -c compares real checksums and prints only files that differ or are missing. No output beyond the file list header means the backup matches.

rsync -rcn --delete -v \
  --exclude='System Volume Information' --exclude='$RECYCLE.BIN' \
  /Volumes/OLDDRIVE/ /Volumes/BACKUP/OLDDRIVE-backup/

Optional, stronger and reusable: record SHA-256 checksums of the backup now, and use the same file to verify the copy that you restore to the exFAT drive. Any line that is not OK is printed.

cd /Volumes/BACKUP/OLDDRIVE-backup
find . -type f -print0 | xargs -0 shasum -a 256 > ~/olddrive.sha256
# after copying back to the new exFAT volume, verify against the saved checksums
cd /Volumes/MYDRIVE
shasum -a 256 -c ~/olddrive.sha256 | grep -v ': OK$'

Only continue to the erase step when every check passes. Keep the backup until the restored copy has been verified as well.

Copying the files back

After the drive is erased and mounted as exFAT, copy everything back, then eject it properly. exFAT has no journal, so always eject before unplugging.

rsync -rtv --progress \
  /Volumes/BACKUP/OLDDRIVE-backup/ /Volumes/MYDRIVE/
diskutil eject /dev/disk4

Then run the checksum verification from the previous section against the new drive. Delete the backup only when everything matches.

When you should not convert

• You only use the drive on a Mac: APFS is faster, safer and supports snapshots, permissions and Time Machine. exFAT is a compromise for sharing.
• You only want to read and write the NTFS drive on your Mac: you do not need to reformat. Install an NTFS driver for macOS and keep your data in place.
• You need files larger than 4 GB on FAT32: use exFAT, not FAT32. FAT32 cannot store a single file of 4 GB or more.
• It is a Windows boot or system drive, a BitLocker drive or a Boot Camp partition: erasing it will break Windows. Do not use this method.
• You need Time Machine: Time Machine cannot back up to exFAT. Use APFS or Mac OS Extended.

exFAT vs APFS vs FAT32 vs NTFS

exFAT also has no hard links, symbolic links, Unix permissions or ACLs, and macOS stores extra metadata for it in hidden "._" files.

Honest risks of exFAT

• No journal: if you unplug the drive without ejecting it, or the power fails during a write, the volume can be left inconsistent and files can be lost. Always eject.
• Cluster size: large drives are often formatted with big clusters (commonly 128 KB or more, depending on the tool), so every small file wastes part of a cluster. A folder with a huge number of tiny files can take noticeably more space than before.
• Not enough backup space: if you cannot hold a complete copy somewhere else, do not begin. Partial backups are how data gets lost.
• It is destructive: erasing the wrong disk cannot be undone. Triple-check the device identifier.
• NTFS-only features such as ACLs, alternate data streams, hard links, junctions and EFS encryption are not preserved. File contents, names and modification times are.

Automating it: NTFS2exFAT

If you only want to read and write an NTFS drive on your Mac without reformatting it, see NTFSTool.

FAQ

NTFS and Windows are trademarks of Microsoft Corporation. Mac, macOS and Time Machine are trademarks of Apple Inc. NTFS2exFAT is an independent utility and is not affiliated with, sponsored by, or endorsed by Microsoft or Apple.