How to Format a USB on a Mac [Complete Steps]
Knowing how to format a USB drive on a Mac is an essential skill for anyone who regularly transfers files, backs up important documents, or prepares a USB drive for use with different devices. Over time, a USB flash drive can become cluttered with unnecessary files, corrupted data, or an incompatible file system that prevents it from working properly. Formatting gives the drive a fresh start by removing all existing data and creating a new file system.
Whether you have purchased a brand new USB drive or want to reuse an old one, macOS includes a built-in utility that makes the formatting process simple. You do not need to install any additional software or have advanced technical knowledge. With just a few clicks, you can erase the drive, select the appropriate format, and prepare it for your specific needs.
Before you begin, remember that formatting permanently deletes everything stored on the USB drive. If the drive contains important files, photos, or documents, make sure you create a backup before continuing.
In this guide, I’m going to explain how to format a USB drive on Mac only.
How to Format a USB Drive on Mac [Complete Steps]
Formatting a USB drive on macOS only takes a few minutes. Follow each step carefully to ensure the process completes successfully.
Step 1: Connect the USB Drive to Your Mac
The first step is to plug your USB flash drive into one of your Mac’s USB ports. If your Mac only has USB-C ports, use a compatible adapter or USB hub if your drive uses a standard USB-A connector.
After connecting the drive, wait a few seconds. Your Mac should automatically detect it. In many cases, the drive will appear on your desktop or in the Finder sidebar under Locations.
If the drive does not appear immediately, do not remove it. Sometimes macOS needs a few extra seconds to recognize external storage devices.
Before moving to the next step, verify that you have connected the correct USB drive, especially if multiple external drives are attached to your Mac.
Step 2: Open Disk Utility
Once your USB drive is connected, you need to open Disk Utility, which is the built-in storage management tool in macOS.
Open Finder, select Applications, open the Utilities folder, and then launch Disk Utility.
Another quick method is to press Command + Space to open Spotlight Search. Type Disk Utility, then press Return to open the application.
Disk Utility displays all storage devices connected to your Mac, including your internal drive, external hard drives, SSDs, memory cards, and USB flash drives.
Take your time while viewing the list because selecting the wrong drive could erase important data from another storage device.
Step 3: Show All Devices
By default, Disk Utility may display only storage volumes instead of the physical drives.
Click View at the top of the Disk Utility window and select Show All Devices.
This option displays the physical USB drive along with any existing partitions beneath it. Selecting the physical device instead of an individual partition ensures the formatting process completely resets the drive.
This step is especially important if your USB drive has multiple partitions or was previously used with another operating system.
Step 4: Select the Correct USB Drive
Look through the list on the left side of Disk Utility and find your USB drive.
The drive name usually includes its storage capacity, such as 32 GB, 64 GB, or 128 GB, making it easier to identify.
Click the top-level USB device instead of any indented volume listed beneath it.
Before continuing, double-check that you selected the correct drive. Formatting cannot be undone, and all existing files will be permanently deleted.
If you are unsure which device is your USB drive, disconnect it, watch which device disappears from Disk Utility, reconnect it, and note which device reappears.
Step 5: Click the Erase Button
With the USB drive selected, click the Erase button located near the top of the Disk Utility window.
A new window will appear asking you to enter several details before the formatting process begins.
This includes the drive name, the file system format, and the partition scheme.
Do not worry if these options seem confusing. The next steps explain each setting in simple language.
Step 6: Enter a Name for the USB Drive
The Name field lets you choose how the USB drive will appear in Finder whenever you connect it to your Mac.
Choose a simple and descriptive name such as Work Files, Backup Drive, Photos, or USB Storage.
You can rename the drive later if needed, so there is no pressure to choose the perfect name right now.
Using a meaningful name makes it easier to identify the drive, especially if you use multiple USB devices.
Step 7: Choose the Correct File System Format
Selecting the correct file system is one of the most important parts of formatting your USB drive.
Choose APFS if the USB drive will only be used with modern Macs running recent versions of macOS. APFS offers excellent performance and works well with Apple devices.
Choose Mac OS Extended (Journaled) if you need compatibility with older Mac computers.
Choose ExFAT if you plan to use the USB drive on both Mac and Windows computers. This is the best option for most people because it supports large files and works across multiple operating systems.
Choose MS-DOS (FAT) only if you need compatibility with older devices. Keep in mind that FAT has file size limitations and is generally not recommended for storing large files.
Selecting the appropriate format now helps avoid compatibility problems later.
Step 8: Select the Partition Scheme
Next, choose a Scheme from the available options.
For most users, GUID Partition Map is the recommended choice because it provides the best compatibility with modern Macs.
If you are preparing the USB drive for a specific device that requires another partition style, follow that device’s instructions instead.
Otherwise, leave the default GUID Partition Map selected.
Step 9: Start Formatting the USB Drive
After reviewing all your settings, click the Erase button.
Disk Utility will begin formatting the USB drive.
The process usually takes only a few seconds for smaller flash drives and a little longer for larger storage devices.
During formatting, avoid disconnecting the USB drive or shutting down your Mac.
Interrupting the process could corrupt the drive and require you to format it again.
Step 10: Wait for the Process to Finish
Once formatting is complete, Disk Utility will display a message confirming that the operation was successful.
Click Done to close the confirmation window.
Your USB drive is now clean, properly formatted, and ready to store new files.
You can safely close Disk Utility and begin using your USB drive immediately.
Step 11: Eject the USB Drive Safely
Before removing the USB drive, always eject it properly.
Open Finder and click the Eject button next to the USB drive, or right-click the drive and choose Eject.
Wait until the drive disappears from Finder before physically unplugging it.
Safely ejecting the drive helps prevent file corruption and protects your data from unexpected damage.
FAQs
Does formatting a USB drive delete everything?
Yes. Formatting permanently removes all files, folders, and partitions stored on the USB drive. Always create a backup before formatting.
Which format should I choose for both Mac and Windows?
ExFAT is the best choice if you want the USB drive to work on both Mac and Windows computers without file size limitations.
Why is my USB drive not showing in Disk Utility?
Try reconnecting the drive, using another USB port, restarting your Mac, or testing the USB drive on another computer. If it still does not appear, the drive may be damaged.
Can I recover files after formatting?
Recovering files after formatting can be difficult. Some data recovery software may help, but success is never guaranteed. Backing up important files beforehand is always the safest approach.
How long does formatting take?
Most USB flash drives format within a few seconds to one minute. Larger storage devices may take several minutes.
Can I format an external hard drive using the same steps?
Yes. The same Disk Utility process works for external hard drives, SSDs, memory cards, and many other removable storage devices.
Summary
Formatting a USB drive on Mac is a valuable skill that helps keep your storage devices working efficiently. By using Disk Utility, you can erase an old drive, prepare a new USB flash drive, or change the file system to improve compatibility with other devices.
The most important part of the process is selecting the correct file system for your needs. APFS is ideal for modern Macs, Mac OS Extended works well with older Apple computers, and ExFAT is the best choice if you regularly switch between Mac and Windows.
Always remember to back up your files before formatting because the process permanently deletes all existing data. After formatting is complete, safely eject the USB drive before unplugging it to prevent file corruption.