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.
Once the download is complete, click on the download manager at the top-right corner of the Safari window and double-click on the file. This will open up a new window. Click on “macOS Catalina Patcher” to proceed further. Click on “Continue” to begin with the macOS Catalina installation procedure. Next, click on “Download a Copy” to.
What you need to create a bootable installer
- A USB flash drive or other secondary volume formatted as Mac OS Extended, with at least 14GB of available storage
- A downloaded installer for macOS Big Sur, Catalina, Mojave, High Sierra, or El Capitan
- This occurs when the copy of the macOS Catalina Installer app used has gotten corrupted somehow. To rectify this, use Catalina Patcher to download a fresh copy of the Catalina installer, then re-create an installer volume and/or retry the installation. The Zoom application does not show any video during meetings.
- MacOS 10.15 (Catalina) was released on 7 October 2019. The newly released update, macOS Catalina, is available to users who are running OS X 10.9 (Mavericks) or later on their Mac. With this latest iteration, Apple replaces macOS Mojave sporting newly updated features.
- Once the drive has been erased, select Install macOS and then Continue. Just follow the on-screen prompts to clean install macOS Catalina Once you’ve successfully installed the new software, you can transfer all your data back from the cloud or external storage drive to the Mac.
Download macOS
- Download: macOS Big Sur, macOS Catalina, macOS Mojave, or macOS High Sierra
These download to your Applications folder as an app named Install macOS [version name]. If the installer opens after downloading, quit it without continuing installation. To get the correct installer, download from a Mac that is 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. - Download: OS X El Capitan
This downloads as a disk image named InstallMacOSX.dmg. On a Mac that is compatible with El Capitan, open the disk image and run the installer within, named InstallMacOSX.pkg. It installs an app named Install OS X El Capitan into your Applications folder. You will create the bootable installer from this app, not from the disk image or .pkg installer.
Use the 'createinstallmedia' command in Terminal
- Connect the USB flash drive or other volume that you're using for the bootable installer.
- 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 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
MyVolumein these commands with the name of your volume.
Big Sur:*
Catalina:*
Mojave:*
High Sierra:*
El Capitan:
* 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:
- Press Return to enter 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
Yto confirm that you want to erase the volume, then press Return. Terminal shows the progress as the volume is erased. - After the volume is erased, you may see an alert that Terminal would like to access files on a removable volume. Click OK to allow the copy to proceed.
- When Terminal says that it's done, the volume will have the same name as the installer you downloaded, such as Install macOS Big Sur. You can now quit Terminal and eject the volume.
Use the bootable installer
Determine whether you're using a Mac with Apple silicon, then follow the appropriate steps:
Apple silicon
- Plug the bootable installer into a Mac that is connected to the internet and compatible with the version of macOS you're installing.
- Turn on your Mac and continue to hold the power button until you see the startup options window, which shows your bootable volumes.
- Select the volume containing the bootable installer, then click Continue.
- When the macOS installer opens, follow the onscreen instructions.
Intel processor
- Plug the bootable installer into a Mac that is connected to the internet and compatible with the version of macOS you're installing.
- Press and hold the Option (Alt) ⌥ key immediately after turning on or restarting your Mac.
- Release the Option key when you see a dark screen showing your bootable volumes.
- Select the volume containing the bootable installer. Then click the up arrow or press Return.
If you can't start up from the bootable installer, make sure that the External Boot setting in Startup Security Utility is set to allow booting from external media. - Choose your language, if prompted.
- Select Install macOS (or Install OS X) from the Utilities window, then click Continue and follow the onscreen instructions.
Learn more
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:
Posted on September 28, 2018 by Paul
Updated 15 October 2019
This is a short note about getting started with Java 11 LTS or Java 13 on macOS Catalina. As you probably know, starting with Java 11 there was a big change in the license under which the official Oracle JDK is provided. In short, you need to buy a license from Oracle if you want to use the official JDK in a commercial setting. As far as I know, using Oracle’s JDK on your private computer for testing and learning purposes is allowed.
That being said, for most users OpenJDK is the new JDK of choice, it is provided under an open source license and you don’t need to pay for using it.
There is also a video version of this tutorial:
At this time, Java 11, the long term release or LTS, of Java is no longer supported on the OpenJDK website. You can still get the archived version, but this is not recommended because it doesn’t include any new security patches. If you still need to use Java 11, use an alternative build like the one from AdoptOpenJDK. From the AdoptOpenJDK page you will download a pkg file that you can install on your macOS machine directly by double clicking on it.
After you’ve installed the AdoptOpenJDKpkg file, check if you can use it with:
This is what I see on my machine:
If you prefer to use the Java version provided by the OpenJDK website, you will need to use Java 13. Start by getting OpenJDK, chose the macOS version. Extract the archive by double clicking on the file or, assuming it is in your Downloads folder, write this in your Terminal:
Macos Install Catalina
Next step, is to move the extracted folder to a place where macOS searches for Java JDK:
Now, check if you’ve successfully installed the JDK with:
This is what I see on my machine:
Mac Os Install Catalina
Just to be sure that everything works, try to compile and run a simple program:
Save the above as HelloWorld.java and compile it with:
If you want to run the compiled version:
This is what I see on my machine:
Side note, you can also run directly the program, without the separate compilation step with:
but this is usually slower than compiling the code with javac and running the compiled code.