How to Create a Bootable Mac USB with DiskMaker

If your Mac is unstable or won't start up, having a rescue tool is essential. One of the most reliable solutions is to create a bootable Mac USB drive, which allows you to reinstall macOS or run diagnostic tools. While there are several ways to do this, DiskMaker X (formerly Lion DiskMaker) is a popular free app designed to simplify this process, making it accessible even for non-technical users.

DiskMaker X automates the technical steps, turning a complex task into just a few clicks. Whether you need to fix a system crash, perform a clean installation of macOS, or set up multiple Macs without redownloading the installer, this guide will walk you through using DiskMaker X. We will provide clear, step-by-step instructions and troubleshoot common errors you might face.

Part 1. DiskMaker Versions and Their Compatibility

Fristly, let's have a look at the basic information of DiskMaker. Below is the list of DiskMaker versions with their compatible macOS X:

Note: DiskMaker X is not compatible with macOS Big Sur, and the developers are not planning to update the software compatibility.

Part 2. Pre-requisite to use DiskMaker

To create a macOS bootable USB with DiskMaker X, you will need the following:

• USB drive: Approximately 8 GB for most macOS versions, but at least 10 GB for macOS Catalina. A multi-boot disk covering every macOS version requires roughly 58 GB.
• Downloaded installer: A full installer for macOS Catalina, High Sierra, or El Capitan.
• macOS installer app: Download it from the Apple official website or the Mac App Store. If it is unavailable there, you can get it from the DiskMaker X download page.
• Data backup: Back up the data on both your USB drive and your Mac system.

Note: USB-C and Drive Speed: Although DiskMaker X works with older USB 2.0 drives, using a USB 3.2 Gen 1 or faster flash drive cuts creation time from about 45 minutes to under 10 minutes. On a modern MacBook with only USB-C ports, make sure your USB-C to USB-A adapter supports data transfer rather than charging only — a high-quality adapter prevents Disk Not Found errors during verification.

Pro Tip: The Mac App Store often downloads a stub installer of around 20 MB, which causes DiskMaker X to fail. Follow the steps below to get the full 5 GB+ installer.

1. Delete any existing Install macOS files from your Applications folder.
2. Open Terminal and run softwareupdate --fetch-full-installer --full-installer-version 10.15, replacing 10.15 with your target version.
3. Wait for the download to finish in your Applications folder — DiskMaker X needs this full file to build the bootable structure.

Part 3. Backup or Recover Lost Data from Unbootable Mac before using DiskMaker

Before using DiskMaker X, back up your data first: if the boot process fails, you risk losing important files. A reliable option is Recoverit, which runs on Mac and can extract data even from an unbootable Mac.

Follow the steps below to create a strong backup with Recoverit.

Prerequisites: a blank USB flash drive with 16–32 GB of free space, and a working computer with Recoverit installed.

1. Launch Recoverit on your working computer and insert the USB drive. On the left of the main interface, choose System Crashed Computer and click Start.

   

2. When prompted to select a bootable device, choose your USB flash drive and click Start.

   

3. The USB drive will be formatted to ensure sufficient space, so back up important files in advance. Click Format and follow the on-screen procedure.

   

4. After formatting, Recoverit creates the bootable media. Do not remove the USB flash drive during this process — it usually finishes within a few minutes and then guides you to boot your crashed Mac.
5. Boot the crashed Mac, connect a good hard drive, select it, and click Start Copy. Wait until the screen shows Copy files completed!

Part 4. How to Use DiskMaker to Create a Bootable USB on macOS?

Here's how to use DiskMaker X to create a bootable USB on different macOS:

• on macOS 10.14 Mojave
• on Sierra and Other Mac OS X

Use DiskMaker to Create Bootable USB on macOS 10.14 Mojave

Follow the below steps to use DiskMaker on macOS Mojave:

1. Download DiskMaker X 8 and install it. Then open the Mac App Store, find the macOS Mojave Installer, click Get, and download it.

   

2. Plug a 16–32 GB USB drive into your Mac and back up its data, because DiskMaker X erases everything on the drive.
3. If you are already running macOS Mojave, grant Accessibility authorization first. Mojave's Privacy Control raises multiple alerts during USB creation; follow the sub-steps below to prevent them.

   

• From the Dock, open System Preferences and click Security & Privacy.
• Go to the Privacy tab and click Accessibility.
• Click the lock icon in the corner to unlock the preference.
• Use Touch ID or enter your password, then drag the DiskMaker X icon from the Finder into the list of apps allowed to control your Mac.

4. Launch DiskMaker X, select macOS 10.14 Mojave, and click Use this Copy.

   

5. Select USB Drive as the target, confirm the erase, enter your admin password if asked, and wait for the booting process to complete.

   

Note: Remove this authorization once you finish creating the bootable USB drive with DiskMaker X. Some alerts may still appear — click OK to dismiss them.

Once done, a dialog box will appear. Click quit or System Preferences, depending on your requirements. Alternatively, install the OS by rebooting your Mac.

Use DiskMaker to Create a Bootable USB on Sierra and Other Mac OS X

To create a bootable USB on macOS Sierra using DiskMaker, follow these steps in sequence:

1. Download the macOS Sierra installer from the Mac App Store.
2. Download DiskMaker X for macOS Sierra and install it. Plug a 16–32 GB USB into your Mac and launch the software.
3. Select macOS Sierra and let the app search for a copy of the OS. When the dialog appears, click Use this Copy — or click Use another copy to pick a different installer.
   
4. Select your thumb drive; the app formats everything on the USB drive. Enter your admin password and the booting process begins.
   
5. Wait for the process to complete, then restart your Mac to install macOS.
   

In case you want to create macOS Bootable usb drive on Windows in another way, you can watch this video:

Part 5. Troubleshooting

When using DiskMaker, you may discounter some common problems on different macOS systems. We have listed the three main problems and provided relevant solutions to help you out.

Part 6. A Quick Verdict: Well-Known MacPE Tools - UNetbootin and DiskMaker, Which to Choose?

Both UNetbootin and DiskMaker X are popular tools for creating bootable USB flash drives. But which one to choose?

The first thing to know about is that they work on different systems. DiskMaker X is a macOS-only tool that allows you to create bootable disk images for macOS installer disks. However, UNetbootin is a free cross-platform tool that enables you to create bootable live USB drives for various Linux distributions and is available for Windows, Linux, and macOS. To learn more about UNetbootin, you can read How to use UNetbootin on Mac.

Below we have provided a quick comparison table to help you decide which software is best for you.

As you can see in the table, UNetBootin is better software than DiskMaker X in many aspects. However, the latter is specifically designed for macOS. Therefore, we recommend to choose the one which best suits your needs.

More Related: How to Boot Mac from USB Drive

Conclusion

In this article, we've discussed how to use DiskMaker X to create a bootable macOS USB for different Mac OS X. We've provided step-by-step methods for using the software on macOS Mojave and Sierra, and shown how to resolve common errors you may encounter while using DiskMaker X on your Mac.

Hopefully, this article helped resolve your queries, and you can now create a bootable macOS USB without any hassle.