macOS – Big Sur Bootable USB

macOS Big Sur is now available for free download from the Mac App Store. With the help of this guide we will explain how to quickly and easily create a bootable USB stick for macOS 11, which is useful if you are having problems with your Mac, or when you place a new drive like here.


Nowadays, the updates are offered with full software. That’s fine, but it also has a downside. Should your Mac suddenly experience problems, you have no physical ability to reinstall macOS. Of course you can always reinstall your Mac via a clean install or Internet Recovery, but you must have a good internet connection. That’s why it’s useful to make a bootable USB stick that you can use to reinstall macOS Big Sur. What do you need? A USB stick or external hard disk / SSD of at least 16 GB and a Mac with OS X 10.6.8 or higher.

Download macOS Big Sur from the Mac App Store

To make a bootable USB stick you of course need the macOS Big Sur installation. You can download this from the Mac App Store. If you are already using the new macOS, you can simply download the installation file again from the Mac App Store. To do this, open the app page and click View / Download. System preferences will then be opened and you can indicate that you still want to download the update.

When your macOS is downloaded, you will see the installation file start automatically. You can close this by clicking with the secondary mouse click (right mouse button) on the installer icon in the dock or via the menu bar. The red dot at the top of the window will in most cases not be visible.

Install USB Stick installation without complicated command

  1. Download ‘Install Disk Creator‘ from MacDaddy
  2. Open the downloaded zip file
  3. Connect the USB Stick to your Mac
  4. Start the Install Disk Creator application
  5. Select the USB stick in the drop-down menu at the top
  6. Then click on ‘Choose a macOS installer

Now navigate in Finder to the installation file (often in the Applications / apps folder). Click ‘Open‘ to add macOS Big Sur to the app. Then click on ‘Create installer‘ to create the bootable USB stick. The Install Disk Creator may not work yet, you will have to wait for the support to be added or use the command below to manually create a boot disk.

Create a Big Sur installation USB stick via Terminal

Attach the USB stick to your Mac, open Finder, and secondary click (right mouse button) on the USB stick in the sidebar. Choose ‘Show info‘, you will now see the full name of the USB stick at the top, you need it.

  • Now copy the command below (command⌘ + C)
  • Paste the command in a text document (command⌘ + V)

Now adjust the command, make sure you type exactly the same name as the name of your USB stick instead of ‘USB‘ (spaces are not supported). Would you rather not change the command? Then you can also give the USB stick the name ‘BIGSUR‘. You do this by formatting the stick via these steps.

  • After that, open Terminal via Applications ▸ Utilities
  • Copy the custom command (command⌘ + C)
  • Paste the command in an empty window (command⌘ + V)
  • Press enter to run the command

The command:

sudo / Applications / Install \ macOS \ Big \ --volume / Volumes / BIGSUR

Terminal will then ask for your password before actually executing the command. Enter this, it is normal that no letters or stars are shown when entering the password. Then you have to confirm the deletion with Y + enter.

Making a bootable USB stick with macOS will take quite some time (15 to 30 minutes, depending on how fast your USB stick can write). You will be able to see the progress in terminal. It is not recommended to close Terminal during this process, Terminal should remain active throughout the process.

How about a Fusion Drive?

Do you have a Mac with an official Fusion Drive? Then it is best to perform a clean install. A Mac with Fusion Drive has a unique version of Disk Utility that handles Fusion Drive settings itself. It may be that macOS Catalina (or earlier) will be reinstalled, then you can update to macOS Big Sur via the Mac App Store.

Boot from an installation USB stick and install

When the process is complete, you can close Terminal and the bootable USB stick with macOS Big Sur has been created. In Finder you will see the USB stick as ‘Install macOS Big Sur‘. If something goes wrong with your Mac in the future and you want to reinstall it with the bootable USB stick, do it as follows:

  • Shut down your Mac
  • Insert the USB stick with macOS into your Mac
  • Turn on your Mac and hold down the option⌥ key
  • Then choose the bootable USB stick (if you are using a USB stick, it will have an orange icon)
  • Start the clean installation procedure

Note: A wired keyboard and mouse is required on an iMac, Mac Mini or Mac Pro!


A bootable USB stick is very easy to make and very useful when needed. Before the Mac App Store was introduced, you were provided with a CD disk to reinstall OS X. In most cases, when your Mac is no longer functioning properly, you will no longer be able to access the Mac App Store. That is why it is wise to create a USB stick to perform a clean installation as quickly as possible.

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