Best Free Way to Clone A USB Flash Drive to Another [Windows & Mac]

In today's digital world, USB drives are still everywhere. They're small, portable, and easy to use — whether you're keeping family photos and documents safe or an IT team is handing out system images, software packages, or classroom materials.

That said, USB drives aren't bulletproof. They can break, get lost, or end up carrying malware, and when that happens, important data can vanish in an instant. There's also the practical problem: if you need the exact same content on dozens of drives, copying files one by one is painfully slow and error-prone.

This is when USB disk cloning really comes in handy. Cloning makes an exact copy of a USB flash drive, including the boot records and hidden data, instead of dragging and dropping files. For both backups and large-scale distribution, it's faster, safer, and much more dependable. This guide will explain what USB flash cloning is, why it's important, and the different ways you can do it.

What is USB flash drive cloning?

Cloning a USB drive means creating a complete, sector-by-sector duplicate of one drive onto another. Unlike simple copy-and-paste, it preserves everything — from files and folders to hidden data and boot records — on the new drive.

That's what makes cloning different. If your source USB flash drive is bootable, a proper clone will give you a bootable copy as well. Try that with regular copy-paste and you'll quickly find it doesn't work.

Cloning vs. copying: what's the difference?

• Copying (the usual way): You only move visible files and folders. System files, partition tables, and boot records don't come along for the ride. A copied bootable USB, for example, won't boot.

• Cloning: Every byte gets replicated, including system-critical and hidden data. The result is a drive that functions exactly like the original. That's why disk cloning is the method of choice for creating backups or bootable media.

Common USB flash drive cloning methods

There's more than one way to clone a USB, and the best choice depends on what you need:

Sector-by-sector cloning

This makes a one-to-one mirror of every sector on the source drive, used or unused. It's thorough and works perfectly for bootable drives, but it can take longer — especially with large capacity sticks.

Clone disk by file system structure

After cloning, the data organization within the partitions on the target USB flash drive will match the source exactly. Any invalid or unused sectors are skipped during the copy process.

Clone by file

Analyzes file organization of each partition on the source USB drive and copies all files from each source partition to the corresponding partition on the target drive. During the process, files on the target are reorganized according to the file system structure, ensuring that the target partitions remain free of file fragmentation.

When might you need to clone a USB flash drive to another?

Cloning a USB flash drive isn't just for IT pros — it's something that can be useful for almost anyone, from personal users to schools, businesses, or even forensic investigators. Here are some of the most common situations where cloning makes sense:

💾 1. Data backup and disaster recovery

This is probably the most frequent reason people clone a USB drive. If your drive contains important files — family photos, work documents, research data, or project files — creating a cloned copy gives you a full backup you can rely on.

If the original USB disk fails because of physical damage (like a broken connector or chip issues), accidental deletion, or even a ransomware attack, the cloned USB drive can step in immediately. And unlike a regular copy, cloning preserves hidden data such as software settings or boot records, so nothing gets left behind.

🚀 2. Make it easy to make more than one bootable USB drive

Many times, you may need more than one identical bootable USB drive. So, you can make a master USB drive first and then clone it to several other drives at once instead of setting up each USB one at a time. This saves hours of work that needs to be done over and over again, keeps all drives the same, and lowers the chance of making mistakes.

🔄 3. System migration and recovery

Some USB drives run portable operating systems, like Windows To Go or Linux Live USB. In these situations, USB drive cloning is very useful:

Move your portable OS to a bigger or faster drive for better performance and storage.

If your portable OS runs into errors or conflicts, a cloned copy lets you restore it immediately — no need to reinstall everything from scratch.

🛠️ 4. Device replacement and upgrades

When your old USB is full, too slow (say USB 2.0 vs USB 3.0), or physically worn, cloning makes moving to a new drive smooth. All your files, settings, and even software configurations come along. You just plug in the new drive, and it works exactly like the old one.

🔒 5. Digital forensics and archiving

Cloning a USB drive to another is a common way to keep evidence in legal, administrative, or corporate audits. A cloned copy lets investigators look at the data without touching the original drive, which keeps the evidence safe and stops accidental changes.

Free Flash Drive Cloner: DiskGenius Free Edition

If you're looking for a reliable, easy-to-use USB cloning tool, DiskGenius is one of the best free options out there. It is not only built as a powerful disk partition and data recovery utility, but also comes with disk cloning features.

DiskGenius gives you the freedom and control you need to back up important files, duplicating bootable media, or manage more than one drive at once.

Main features:

• Sector-by-sector clone: Copies every sector, including unused space and boot records, giving you a perfect mirror of the original drive.

• File system structure clone: Duplicates partitions and file system structures while making the most of available space.

• File-level clone: Copies only files and folders, skipping empty sectors for faster results. This is ideal for everyday data transfer.

• DiskGenius works with all major Windows versions, from Windows XP to Windows 11, and supports USB 2.0, 3.0, and 3.1 drives. It can also work with many different file systems, such as FAT32, NTFS, exFAT, and EXT4.

• Bootable USB cloning. You can clone USB drives that contain operating systems, and DiskGenius will preserve all boot records. The result? A fully bootable cloned drive — perfect for system installers or portable OS drives.

• Partition resizing during clone. Need to make better use of storage? DiskGenius lets you adjust the partition size on the target USB flash drive during cloning, which is handy when moving to a larger drive.

• Sector editing for advanced users. For those who like to dig deeper, DiskGenius allows direct sector-level editing. It's a useful feature for troubleshooting issues via editing hex data.

• Clone to multiple target drives at once. If you need more than one copy, DiskGenius can clone a single source disk to multiple targets simultaneously. This saves tons of time and keeps all your drives consistent.

• Clone disk with bad sectors. Are you worried that your drive will fail? The "Copy Sectors" feature can skip bad sectors while still executing the sector-level disk cloning.

DiskGenius is a great choice for anyone who needs to clone USB drives because it has both easy-to-use tools and advanced features. And since it's free, it's a great starting point before considering more specialized enterprise-level tools.

Clone a USB Flash Drive to another on Windows

It's easy to clone a USB drive on Windows with DiskGenius doesn't require any complicated setup.

✅ Get your drives ready:

1. Connect both the source USB flash drive (the one you want to copy) and the target USB flash drive (the one that will get the data). Let Windows take a moment to see them. If one doesn't show up, try plugging it back in or using a different USB port.

2. Check the target drive's capacity. For sector-by-sector cloning, the target USB drive must be equal to or larger than the source; For file-level cloning, it only needs to be as large as the used space on the source drive.

3. Backup important files for the target USB disk. The cloning process will surely erase everything on the target disk, so you should make sure to copy anything you need to a different place first.

4. Install DiskGenius Free Edition: Download it from the official website (www.diskgenius.com) and install it on your Windows PC.

✅ Start the cloning process:

Step 1. Launch DiskGenius, and you can locate the source and target USB flash drives on the left. You can identify them by name and size, for example, Kingston DataTraveler 3.0 (16GB).

Step 2. Click "Tools" → "Clone Disk".

Step 3. Choose the flash drive you want to clone as the source disk and click "OK".

Step 4. Select the target USB disk from the list and click "OK".

⚠️ Caution: All data on the target drive will be erased. Double-check you've picked the correct device.

Step 5. Select a cloning method:

"Copy all sectors" is the sector-by-sector disk cloning, and it creates an exact bit-for-bit copy. So, it's appropriate for bootable drives or forensic-level duplication.

"Copy valid data sectors only" copies data according to the file system layout. Faster than sector-by-sector and good for most uses.

"Copy all files" is the file-level disk cloning. It only transfers files and folders, skipping unused space. This is the quickest method.

Step 6. Click "Start". Another warning that the target disk is going to be erased will appear. Click "OK" to confirm.

Step 7. Wait for the cloning process to finish.

It can take anywhere from a few minutes to more than an hour, depending on the drive size and cloning method.

Important: While disk cloning is going on, do NOT unplug USB drives or close DiskGenius. Interrupting the process will cause errors or incomplete cloning.

🎞️ Prefer a visual guide? Watch our step-by-step YouTube video to see how to clone a USB drive quickly and easily.

Clone Flash Drive to Flash Drive on Mac

Cloning a USB drive on macOS works a little differently from Windows because Mac uses file systems like APFS and HFS+. The good news is that you don't need any third-party apps — macOS comes with Disk Utility, which makes cloning a standard data USB fairly straightforward. Here's how to do it.

Step 1. Prepare your USB drives.

1. Check capacity and back up data: Make sure your target USB has enough space to hold everything from the source drive. Remember, this process will erase everything on the target, so back up any important files first.

2. Insert both drives: Plug in your source USB (the one you want to copy) and your target USB. If your Mac doesn't have standard USB ports, use a USB adapter or hub.

Step 2. Open Disk Utility.

Open Finder and go to the Applications folder.

Navigate to Utilities and double-click Disk Utility.

Step 3. Create a disk image of the source USB.

macOS doesn't allow direct "disk-to-disk" cloning in Disk Utility. Instead, you first create an image of the source USB, then restore that image to the target.

In the Disk Utility sidebar, select your source USB (make sure to select the entire disk, e.g., Kingston 16GB, not just a single partition).

From the top menu, click File → New Image → Image from [USB name].

In the pop-up, pick a place to save the disk image. Check to see if it has enough free space.

For Format, choose Compressed (saves space) or Read/Write (lets you modify the image later).

For Encryption, leave it as None unless you want to password-protect the image.

Click Save. The Disk Utility will make the disk image and show a bar that shows how far along it is. The new image will show up in the sidebar when it's done.

Step 4. Restore the image to the target USB.

In the sidebar, select your target USB (again, select the disk itself, not just a volume).

From the top menu, click Restore.

In the Source field, choose the disk image you just created. In the Destination field, select your target USB.

Confirm your selections and click Restore. macOS will warn you that all data on the target USB will be erased.

Type in your Mac administrator password to give permission. Disk Utility will now copy the image to your target USB, which is like making a copy of it.

Step 5. When the restore is done, take out the target USB and plug it back in. Open it in Finder to see what's inside, You have successfully cloned your drive if the files, folders, and structure are the same as on the original USB.

Important Tips for Cloning a USB Drive

📌 Make sure the target drive is big enough. If you're doing a sector-by-sector clone, the target USB must be at least the same size as the source drive. For example, a 32GB source USB disk needs a target of 32GB or larger. If you're cloning by files, the target disk only needs to be larger than the used space on the source.

📌 Don't unplug the drives while cloning. A loose connection can corrupt data. Short cables or USB extensions help keep the drives stable. Also, prevent your computer from going to sleep during the process:

📌 Before cloning, check the health of USB drives. Back up data and repair bad sectors if there are too many of them.

📌 Cloning will completely erase target USB flash drives, so please make sure you have copied any important files to a different place before you start.

📌 Double-check source vs. target. It's easy to mix them up. Always confirm which USB stick is the source and which is the target.

📌 After the cloning is done, open the target USB disk and check if all the files are still there, especially the big or hidden ones. Check to see if it can really start your computer if it's a bootable USB.

📌 Some antivirus programs might see disk cloning as suspicious and stop it. Turn off your antivirus software while cloning to avoid problems, and then turn it back on afterward.

Frequently Asked Questions About USB Flash Drive Cloning

1. Can Rufus clone a USB drive?

No, Rufus isn't meant to clone whole drives. The main thing it does is write ISO files to a USB stick so that you can boot from it. To make an exact copy of a USB drive, including hidden files, boot records, and partitions, you'll need a special cloning tool like DiskGenius.

2. How can I clone my entire OS to a bootable USB stick?

You can move Windows OS to a USB drive with DiskGenius Free Edition:

- Start DiskGenius and click "OS Migration".

- Select the USB stick as the target disk.

- Choose "Set target disk to boot system via USB" .

- Start the Windows migration.

- When the process is over, the USB stick will be bootable.

📒 Related reading: How to Copy Existing Windows 10/11 to USB and Make It Bootable [FREE]

3. How do I copy from one USB stick to another?

You can do it in a few different ways:

Copy and paste by hand. Open both USB sticks in File Explorer and drag files over. This works for some files, but it won't copy system or hidden data.

USB cloning software. Tools like DiskGenius can clone the entire USB stick, including hidden partitions, boot records, and file system structures. The target drive ends up working exactly like the original.

4. Can you tell if a USB has been copied?

Usually, a simple copy-paste leaves no obvious signs. That said, That said, some forensic tools can find timestamps, access logs, or other metadata that show a copy. Encryption is a safer way to protect sensitive data than relying on it not being detectable.

5. How can I identify a fake USB drive?

Fake USB drives often say they have more space than they really do. To spot them:

Use a third-party tool to test how much space they really have.

Test write speeds—fake drives are typically much slower.

Buy only from trusted sellers or official resellers to reduce the risk of counterfeit products.

6. What is a USB duplicator?

A USB duplicator can copy data from one master USB drives to multiple target drives at the same time. People often use it to quickly and easily give out a lot of the same USB sticks.