Before you try to use a bootable installer to downgrade your Mac if you have a 2018 or newer MacBook Pro, MacBook Air, or Mac mini, you may need to make sure to allow booting from external media before you attempt to downgrade. If you've enabled the Startup Security Utility, check to make sure you'll be able to use a bootable external drive.
This is the official macOS Sierra Installer from the Mac App Store. Un-archive the zip and you will get the.app for installing Sierra. A bootable ISO or bootable USB can be made from this installer. First the disk will be deleted, then the entire installer will be copied to your disk. The process will take a while, but when it’s done you’ll have a bootable drive with the installer. Notice that the Utilities folder, offered by DiskMaker X, is not here. The command above is specifically for High Sierra (and a disk named “Installer.”). Sep 26, 2016 Creating a bootable USB installer for macOS Sierra. Follow these steps to create a bootable USB installer. Insert the USB flash drive into a USB port and note the volume name of the drive as it.
These advanced steps are primarily for system administrators and others who are familiar with the command line. You don't need a bootable installer to upgrade macOS or reinstall macOS, but it can be useful when you want to install on multiple computers without downloading the installer each time.
MyVolumein these commands with the name of your volume.
* If your Mac is using macOS Sierra or earlier, include the
--applicationpath argument and installer path, similar to the way this is done in the command for El Capitan.
After typing the command:
Yto confirm that you want to erase the volume, then press Return. Terminal shows the progress as the volume is erased.
Determine whether you're using a Mac with Apple silicon, then follow the appropriate steps:
A bootable installer doesn't download macOS from the internet, but it does require an internet connection to get firmware and other information specific to the Mac model.
For information about the
createinstallmedia command and the arguments you can use with it, make sure that the macOS installer is in your Applications folder, then enter the appropriate path in Terminal:
A bootable installer is a special type of media that can be used to reinstall operating system or fix system issues that never be solved in usual way. When there is something with your Mac, or you urgently need to upgrade your Mac to the latest version of macOS, a bootable installer could be a great help.
This tutorial tells you how to easily create a bootable installer for macOS on both Windows and Mac.
Before getting started, you should know there is only two types of installation media for macOS. One is the official macOS installation app, which is only available from Mac App Store. The other is macOS dmg file, which is made by third-party developers or system administrators.
macOS is the native operating system for all Mac computers. And Apple provides an official tool to create bootable USB installer from macOS installation app with the help of Terminal command, which is totally free. In addition, it is also possible to make a bootable macOS installer from DMG file. We will show examples for both tactics.
This is the most reliable way to make bootable macOS installer on Mac as it is backed by Apple. It is completely free and no need to download additional software for this purpose.
First, download macOS from Mac App Store. Just launch App Store app on your Mac and search for the macOS name. However, only the most recent versions are available for download, including Big Sur, Catalina, Mojave and High Sierra. After that, click the Get button (Big Sur as example) to download the installation app on your Mac.
The downloading process will take more than 15 minutes as the file size is pretty big (Over 8GB). When it is completed, you will see a
Install macOS [version name] app in Application folder.
Now, insert an USB drive into Mac. If everything goes fine, you will see the drive name in left sidebar of Finder app. Then, open Terminal app and type the following command to find the actual volume name of USB drive, which will be used in next step:
In above example, the volume name of my USB drive is
Finally, copy one of the following commands to Terminal and change the volume name. Click Enter to start creating a bootable installer for macOS.
sudo /Applications/Install macOS Big Sur.app/Contents/Resources/createinstallmedia --volume /Volumes/Big Sur
sudo /Applications/Install macOS Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/Big Sur
sudo /Applications/Install macOS Mojave.app/Contents/Resources/createinstallmedia --volume /Volumes/Big Sur
sudo /Applications/Install macOS High Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/Big Sur
You have to wait at least 10 minutes for the above task to be finished. After that, you can use the bootable USB installer for macOS reinstallation, downgrade or upgrade.
If you are scared of using text commands in Terminal, please don't worry. There are still two free GUI app available for this task. One is MDS and the other is Disk Marker X. We will go with MDS first.
MDS is popular Mac deploying tool developed by Twocanoes. It can help you set up Mac, download macOS, create bootable macOS installer, install macOS and configure macOS in just a few seconds. Most importantly, it is built upon a modern graphics user interface, making it super easy to use.
First, download MDS from this link and install the app on your Mac. Once loaded, navigate the left sidebar and find go to Download macOS, where you can download the desired macOS. Currently available versions are Big Sur, Catalina, Mojave and High Serria.
After download, please move to Create macOS Installer section. Please select the macOS installer you just downloaded and a target USB drive. Finally, click the Create button to begin making a bootable USB installer for macOS.
Disk Marker X is another free app with the sole purpose for creating a bootable macOS disk. It has been available since Mac OS X Lion (10.7) so it is very popular and reputable solution. The only drawback is that it does not support macOS Big Sur. You can create bootable installer from the following OS candidates.:
The steps are also quite simple. First, download a macOS installation app and open Disk Maker X. Next, select the location of macOS install app and pick up the drive name. Confirm the operation as it will erase the whole disk. Finally, click Erase then create the disk button to start the process.
In case, you are unable to download the official macOS installation app, an alternative choice is to make a bootable installer from macOS dmg file, where you can find them on this website or other places on Internet. The software to be used is called UUByte DMG Editor, which works on both Windows and macOS platforms. The details steps will be shown in next section.
Windows, even Windows 10 does not add support for dealing with macOS installation app, which is working on macOS only. If you are on a Windows computer and search for a way to create bootable installer for macOS, the only option is by using macOS DMG file.
So in the coming section, we will demonstrate on how to create a bootable installer for macOS from dmg file on a Windows 10 PC. The steps are the same on Windows 8 and Windows 7. The software we are going to use is UUByte DMG Editor, a cross-platform app that runs well on Windows and Mac.
Step 1: Download a macOS DMG file. These are download links of macOS DMG file, such as Big Sur, Catalina, Mojave, High Sierra, and EI Capitan. For old Mac OS X versions, please download it from Internet.
Step 2: Install DMG Editor on a Windows computer and open it after installation. Now, plug a USB disk into Windows and click Burn button from the main screen. Make sure eject other USB storage devices at the same time.
Step 3: Click the Browse button to locate the macOS dmg file you have downloaded and select the USB drive name in below column.
Step 4: Finally, click the Start button to create a bootable installer for macOS on Windows 10.
Step 5: For a fast USB 3.0 drive, you need to only wait a couple of minutes. For slow USB 2.0 drive, you should wait more than 20 minutes. Please be noted! You will see a notice on screen when the burning process is completed.
There are few tools that are capable of creating macOS bootable USB on a Windows machine. For this task, UUByte DMG Editor is good to go!
Eject the USB from Windows 10 computer and plug it into your Mac. Reboot your Mac and keep pressing the Option key at startup to bring up the boot manager. Pick up the drive name and boot up from external USB. After that, follow the screen prompt to start installing macOS from USB on target Mac.
The above is a complete tutorial for creating a bootable installer for macOS on Windows and Mac. It covers all the details and being verified on four different computers (MacBook Pro, iMac, Windows 10 PC and Windows 7 Laptop). Please go ahead and pick up the best method for you.