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 install macOS, but it can be useful when you want to install on multiple computers without downloading the installer each time.
Download macOS
Download a macOS installer.* You can find the appropriate download link in the upgrade instructions for macOS Catalina, macOS Mojave, macOS High Sierra, macOS Sierra, and OS X El Capitan.
- If the macOS installer opens after downloading, quit it without continuing installation.
- macOS Sierra and El Capitan download as a disk image that contains an installer named InstallOS.pkg or InstallMacOSX.pkg. Run this installer before continuing.
- If downloading macOS Catalina, macOS Mojave, or macOS High Sierra for the purpose of creating a bootable installer, your Mac must be using macOS Sierra 10.12.5 or later, or El Capitan 10.11.6. Enterprise administrators, please download from Apple, not a locally hosted software-update server.
Then find the installer in your Applications folder as a single ”Install” file, such as Install macOS Catalina.
Be sure you format the drive and set the partition as GUID, GUID is what makes it bootable. Also be sure the process completes, it can take a while to make the drive. And of course, it will only boot a Mac compatible with OS X El Capitan. If you’re interested in creating a bootable USB flash drive containing Apple’s OS X El Capitan then it’s logical to assume that it’s because you ultimately want to install a fresh copy of the platform onto one of your Mac computers. Or it’s because you want a copy handy in case anything goes wrong with your machine.
Use the 'createinstallmedia' command in Terminal
- Connect the USB flash drive or other volume you're using for the bootable installer. Make sure that it has at least 12GB of available storage and is formatted as Mac OS Extended.
- Open Terminal, which is in the Utilities folder of your Applications folder.
- Type or paste one of the following commands in Terminal. These assume that the installer is still in your Applications folder, and MyVolume is the name of the USB flash drive or other volume you're using. If it has a different name, replace
MyVolume
in these commands with the name of your volume.
Catalina:*
Mojave:*
High Sierra:*
Sierra:
El Capitan: - Press Return after typing the command.
- When prompted, type your administrator password and press Return again. Terminal doesn't show any characters as you type your password.
- When prompted, type
Y
to confirm that you want to erase the volume, then press Return. Terminal shows the progress as the bootable installer is created. - When Terminal says that it's done, the volume will have the same name as the installer you downloaded, such as Install macOS Mojave. You can now quit Terminal and eject the volume.
* If your Mac is using macOS Sierra or earlier, include the
--applicationpath
argument, similar to the way this argument is used in the commands for Sierra and El Capitan.Use the bootable installer
After creating the bootable installer, follow these steps to use it.
- Connect the bootable installer to a compatible Mac.
- Use Startup Manager or Startup Disk preferences to select the bootable installer as the startup disk, then start up from it. Your Mac will start up to macOS Recovery.
Learn about selecting a startup disk, including what to do if your Mac doesn't start up from it. - Choose your language, if prompted.
- A bootable installer doesn't download macOS from the Internet, but it does require the Internet to get information specific to your Mac model, such as firmware updates. If you need to connect to a Wi-Fi network, use the Wi-Fi menu in the menu bar.
- Select Install macOS (or Install OS X) from the Utilities window, then click Continue and follow the onscreen instructions.
Learn more
For more information about the
createinstallmedia
command and the arguments that you can use with it, make sure that the macOS installer is in your Applications folder, then enter this path in Terminal:Catalina:
Mojave:
High Sierra:
Sierra:
El Capitan:
Here’s how to make a bootable installer of El Capitan on a USB Thumbdrive. It is the quickest way but it uses the terminal so it is for advanced users. If you want a way that is slightly longer but easier for beginners download and run Diskmaker which does the steps below for you automatically!
How to make a bootable El Capitan Installer.
- Download and keep a copy of the ‘Install OS X El Capitan’ App. (Download from App store but make a copy of it before you install it as the Apple Installer deletes it after you use it.)
- Put it in your ‘Applications’ folder
- Format your blank USB (8GB is a good size) as Apple OS X Extended (Journaled) using Disk Utility and call it ‘Untitled’
- Open Terminal and type in this:
sudo /Applications/Install OS X El Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install OS X El Capitan.app --nointeraction
You will get a response like this:
And after half an hour or so the USB drive will be a bootable OS X El Capitan Installer that you can use to install or upgrade OS X!
For more info check out the Apple Support article here:
https://support.apple.com/en-us/HT201372
If you have trouble with DiskMaker X here is a way to do it using the built-in Disk Utility in OS X.
Related posts:
Upgrading OSX to the latest versionHow to reset the OS X InstallerHow to install OSX Lion on multiple computersHow to install Lion from scratch if you don’t have Snow Leopard.7 ways to make your Mac boot faster.Virginiesays:November 13, 2016 at 12:20 pmHi again.
I’m trying to find the app “‘Install OS X El Capitan” on App store, but I only find “apps for ipads” or “apps for iphones”. What am I doing wrong? Where exactly should I look? Is it the exact name “Install OS X El Capitan”?
My Mac is too old to get access to the app store. If I have access from a PC, can I still download the app on a USB, save it in the application folder from the USB that I’ve previously formatted on the Mac?
Sorry, I’m just stuck right now…
ReplyWayneI’m trying to find the app “‘Install OS X El Capitan” on App store, but I only find “apps for ipads” or “apps for iphones”. What am I doing wrong? Where exactly should I look? Is it the exact name “Install OS X El Capitan”?
My Mac is too old to get access to the app store. If I have access from a PC, can I still download the app on a USB, save it in the application folder from the USB that I’ve previously formatted on the Mac?
Sorry, I’m just stuck right now…
says:November 13, 2016 at 12:25 pm
App Store is in the Apple Menu in OS X. You can only download the latest version of OS X from the App Store, so at the moment the only version available will be macOS Sierra. So you will need to download “Install mac OS Sierra”.
If you have previously downloaded El Capitan it will be available for you. So if you want an old OS you need to find a person you know who has previously downloaded it as it will be available in the App Store for them.
ReplyIf you have previously downloaded El Capitan it will be available for you. So if you want an old OS you need to find a person you know who has previously downloaded it as it will be available in the App Store for them.