Creating a bootable USB installer for the latest macOS Catalina helps in many ways. One of the reasons why you may want to do it is because it lets you do a fully clean installation of the update on your Mac. The other areas where you can use a macOS bootable installer is when you have multiple Macs and you wish to install the same update on all of them.

1. Bootable Catalina Install Usb
2. Bootable Catalina Iso
3. Bootable Catalina Installer
4. How To Make A Bootable Catalina Drive

How to Create macOS Catalina Bootable USB Flash Drive Installer Using Terminal Here’s how to create macOS Catalina 10.15 bootable USB flash drive installer for a clean install on your Mac. With macOS Catalina being Apple’s latest software release, it stands to reason that there is going to be a big interest in it. When finished, you will see the following Install macOS Catalina in your Applications folder. Format the USB Disk. Now insert your USB disk and then open Disk Utility. We are going to format our USB flash disk. Select your disk from the left panel and then click Erase. Give a name such as “usb” or anything. Then follow these steps to create your bootable macOS Mojave drive. Connect your drive to your Mac. Launch Install Disk Creator. In the main window, you’ll see a pop-up menu under. A bootable version of the macOS Catalina installer is one of the often-overlooked tools a Mac user should have on hand before upgrading to or performing a clean install of Catalina. The bootable installer you create in this guide will be housed on a USB flash drive, but you can use any bootable device you may have lying around, including.

By having a single USB installer, you won’t have to download the update on each of your Macs. The same USB drive can be used to upgrade all of your Macs to the latest version available on the drive.

All it requires you to have is a USB drive with at least 8GB of memory space available on it. You can then either use an application or a few commands in the Terminal app on your Mac to turn your drive into a macOS installer. We show you how to do both below.

Download The macOS Catalina Update On Your Mac

The first thing you’ll want to do is download the entire update on your Mac. You’ll then put this downloaded file as an installer on your USB drive.

• Launch the Mac App Store and search for and click on macOS Catalina.

• Click on Download on the following screen to download the update.

• Sit back, relax, and wait for the update to finish downloading on your Mac.

It’s quite a large update and will probably take an hour or so to fully download on your machine. The download time also depends on how fast your Internet speed is.

Make sure not to proceed with the installer that opens after the update is downloaded.

Create a macOS Catalina USB Installer Using Disk Creator

One of the easiest ways to create a bootable installer for any macOS update, including Catalina, is to use the Disk Creator app. It’s a simple program that allows you to load your update and then create an installer based on that update.

It has a graphical user interface so you don’t need to play around with any commands. Also, keep in mind the app will erase all the existing data stored on the USB drive. Make sure you’ve backed up your important files before you do the procedure.

• Head over to the Disk Creator website and download the package to your Mac. Extract files from the downloaded archive and launch the main application file.
• There are only a handful of options on the main app interface. The first thing you’ll want to configure is the destination for the installer. Click on the dropdown at the top and select your USB drive.

• Next up, click on the Choose a macOS installer button to choose the macOS Catalina update you’ve downloaded to your Mac.

• Once you’ve given the app both your USB drive and your Catalina file, click on the Create Installer button at the bottom of the app to begin the process.

• Wait for a few minutes for the USB installer to be created. When it’s done, you’ll see a success message on your screen.

Your USB installer to install macOS Catalina is now ready. Plug it into any of your Macs that need an upgrade to this version of the macOS.

Use Terminal To Make A macOS USB Installer

If you’re the kind of user who doesn’t trust third-party apps, especially when installing entire operating systems, you don’t necessarily have to use Disk Creator to create the installer.

You can use the Terminal app on your Mac to create the USB installer and that too with just a few commands. Again, all that you’re going to need is an 8GB or larger USB drive and the macOS Catalina update file.

• Open the Terminal app on your Mac, type in sudo, press Space, but don’t hit Enter just yet.
• Launch a Finder window, open the Applications folder, find the macOS Catalina update, right-click on the file, and select the option that says Show Package Contents.

• Open the Contents folder followed by Resources. Find the file named createinstallmedia and drag and drop it onto your Terminal window. It’ll fill-in the update path.

• In the Terminal window, press Space, type in –volume, press Space, and drag and drop your USB device from the Finder onto the Terminal window. It’ll enter in the full path of your USB drive.

1. Hit Enter and since it’s a sudo command, you’ll be asked to enter your password. Enter the password and proceed.

• Press the y key on your keyboard and hit Enter to erase the drive and put your Catalina installer on it.

It’ll start erasing your USB drive to then turn it into a bootable installer. Allow it a good amount of time to finish. Just keep an eye on your Terminal window and you’ll know when it finishes creating the installer.

Bootable Catalina Install Usb

How To Use The macOS Catalina USB Installer

Once a USB installer is created and you’ve got as much excitement to install the update as we do, you’ll just need to follow a few steps so your Mac boots from your installer.

There are two ways you can use your newly created installer.

Use System Preferences To Boot From USB Installer

The first method is to change a startup option so your Mac boots from the USB installer instead of your current boot disk.

1. Click on the Apple logo and select System Preferences.
2. Select Startup Disk, choose your USB drive, and hit Restart.

Your Mac will reboot and it’ll boot-up from your Catalina installer letting you perform a full clean installation of the operating system.

Boot Directly From The USB Installer

This method doesn’t require you to change any startup settings to use the installer.

1. Power off your Mac.
2. Turn your Mac on and hold down the Option key.
3. Select your USB installer from the list and proceed with installation.

You’ll then follow the standard macOS installation steps to upgrade your Macs to this newer version of the operating system.

After months of waiting, macOS Big Sur was released in November 2020. No matter how great macOS Big Sur is, you can experience performance issues as you update your Mac. The good thing is you can downgrade to the previous macOS version.

There are two ways to revert from Big Sur to Catalina. The first one involves restoring a Time Machine backup. The second, which is a bit lengthy, explains how to downgrade to Catalina using a bootable installer. Whichever way you choose, we'll provide step-by-step instructions to help you downgrade.

Open this article on your phone to make sure you do everything step-by-step.

How to downgrade from macOS Big Sur using Time Machine

If you’ve backed up your Mac with Time Machine before upgrading to Big Sur, downgrading to Catalina will be easy. Here’s how to downgrade from macOS Big Sur to Catalina using Time Machine.

1. Back up your data

First, back up everything. Your Mac probably contains your personal data and documents that you don’t want to lose. So, to keep those alive after the downgrade, you need to back up your data.

You can use Google Drive, iCloud Drive, or any other cloud you prefer. After the backup is done, you can move on to the next step.

Before you begin reverting your Mac to macOS Catalina, it’s worth trying fixing performance issues on macOS Big Sur. Maybe you won’t need to downgrade at all.

CleanMyMac X can help identify and solve performance problems on your Mac. It’s a dedicated Mac cleaner that clears old junk and runs optimization tasks. It’s notarized by Apple, which means it’s safe for your Mac. Get CleanMyMac X for free to run a quick performance scan.

2. Erase your Mac’s hard drive

The first step is plugging your Mac into power (the downgrade process may take a while, and you don’t want your Mac to power off unexpectedly).

You’ll need to erase your Mac’s drive. This will remove everything from your Mac, but you can restore your data later from a Time Machine backup.

1. Restart your Mac (Apple menu > Restart).
2. Hold Command-R when your Mac’s rebooting. The Utilities menu should appear.
3. Choose Disk Utility.
4. Click Continue and select Startup Disk (usually located at the top of the list ).
5. Press Erase.
6. Select the APFS file format.
7. Choose GUID Partition Map and confirm.

Wait for the process to complete. Only after every piece of data is removed, can you clean install macOS Catalina.

3. Use Time Machine to restore your backup

You can now restore all your files and data and bring your Mac back to the condition it was in before you installed macOS Big Sur.

If your Time Machine backup is stored on the external drive, plug it in your Mac.

So, to restore your Time Machine Catalina backup:

• Restart your computer and hold Command-R when it reboots.
• Select the Restore From Time Machine Backup option on the Utilities window.
• Press Continue.
• Choose your Time Machine backup disk.
• Select the backup you want to restore from. Choose the most recent backup that occurred before you installed macOS Big Sur.
• Then, select a destination disk, where the contents of your backup will be stored.
• Click Restore and press Continue.

The process may take some time. Your Mac will restart running macOS Catalina.

How to downgrade from macOS Big Sur using a bootable installer

If you didn’t back up your Mac with the Time Machine, it’s too bad. But, you can still downgrade to the previous OS version. Just follow the instructions.

1. Back up your files and data

Backing up your data is important. It prevents you from losing all the files and data that have existed on your Mac's drive for a while. So, don’t forget to back up your Mac before you start downgrading to Catalina.

2. Create a bootable installer

A bootable installer will help you safely roll back to Catalina. Here’s how to create a bootable installer:

1. You can go to the App Store and search for Catalina, then download it. Quit the installer, if it tries to install the OS.
2. If your Mac already runs macOS Big Sur, download the macOS Catalina here.
3. Get an external hard drive that has at least 12 GB of available storage and plug it in your Mac.
4. Launch the Disk Utility app and erase your hard drive selecting Mac OS Extended format.

Now, it’s time to transfer your Catalina installer to your hard drive:

1. Open Terminal (Applications > Utilities).
2. Paste this command and press Enter:

sudo /Applications/Install macOS Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume

The downloaded file, which is your bootable Catalina installer, should be in your Applications folder. MyVolume is the name of the hard drive; if your hard drive or flash drive has a different name, replace MyVolume with the name of your hard drive.

1. If prompted, enter your administrator password and press Enter again. Terminal won’t show anything when you type your password.
2. Follow the instructions that appear in the Terminal.
3. When Terminal says “done”, your hard drive should have the same name as the installer you downloaded (for example, Install macOS Catalina).

Quit Terminal and eject the hard drive.

Install macOS Catalina

Now, you can roll back from macOS Big Sur using the bootable installer.

• Plug your hard drive (which is now your bootable installer) into your Mac.
• Open System Preferences > Startup Disk. Choose your bootable installer as a startup disk and press Restart.

Bootable Catalina Iso

• Your Mac should start up to macOS Recovery.
• Make sure your Mac has an internet connection to download firmware updates (you can use the Wi-Fi menu in the menu bar).
• In the Utilities window, select Install macOS.
• Click Continue and follow the on-screen instructions.

Your Mac will then start installing macOS Catalina and will restart when it’s done.

Mac runs slowly after the update?

If your Mac is slow after the update, but you don’t want to perform this lengthy process and revert to the previous OS, you could try a quick solution. CleanMyMac X has a helpful Maintenance feature that could fix all possible problems on your Mac.

1. Open CleanMyMac X.
2. Go to the Maintenance module.
3. Press View All 9 Tasks.
4. Check the boxes next to the maintenance tasks you want to run.
5. Press Run.

Bootable Catalina Installer

Wait till CleanMyMac X runs the set of fixes to speed up your Mac.

How To Make A Bootable Catalina Drive

Reverting to the previous macOS may seem like a terrifying task. But if you open this article on your phone or another device and follow the instructions, it will be much easier and faster. Don’t forget to clear your Mac before the backup – you will save a lot of free space and remove old clutter that slows down your machine.