macOS Catalina is a hugely exciting upgrade for the Mac. In some ways, it’s like having a completely new computer. You may have already taken the plunge and installed it, or maybe you’re waiting to see how it settles down before you install it. But whichever camp you’re in, it’s a good idea to create a bootable installer for macOS Catalina. That way, if anything goes badly wrong with your Mac, you’ll be able to boot from the installer and get going again quickly.
Why do I need a bootable installer for macOS Catalina?
There are a number of reasons for creating a bootable USB Mac installer.
- If you have more than one Mac, it allows you to install Catalina on all your other Macs without having to download it from the App Store each time.
- You may want to clean install Catalina, in which case you’ll completely wipe your startup disk and will need to boot from an external drive to do that.
- It’s good protection against a catastrophe striking your Mac’s startup disk, especially if you don’t have a stable internet connection. Normally, if you need to reinstall macOS, you can just boot from the recovery partition and do it from there. However, that means re-downloading the installer. So, if you don’t have an internet connection or it’s very slow, you need an alternative.
What should I use as a bootable installer?
You can use an external hard drive, an SSD or a USB stick. Anything that has at least 16 GB of free space. You’ll need to create a new partition (or container if it’s formatted as AFPS) for the installer so if you have data on it you need, you should copy it to another drive first.
Bootable USB Stick - macOS X Catalina 10.15 - Full OS Install, Reinstall, Recovery and Upgrade. Please CHECK twice if your Mac model is compatible with this macOS!! If you are not 100% sure please message me your mac model and year and I can tell for sure if would work or not! Download the macOS Catalina installation file using this link; Turn off the Mac and then insert the bootable USB drive; Now turn the Mac back on while holding the Option key; It will take you to the boot menu where you can select the USB drive. If your Mac has the T2 security chip, you have to first enable booting via external drives from macOS. Mac OS X Catalina 10.15.7 Bootable USB Flash Drive Installer. 1 Helpful Judy Hernandez Apr 20, 2021 5 out of 5 stars. Has instructions! So helpful 👍🏽.
How to create a bootable USB drive for macOS Catalina
Whoa! Not so fast. There’s one more thing you should do before you create the installer: clear out the junk on your Mac. Before you undertake any major task on your Mac, and especially before you install a new version of the operating system, you should clear out junk and old files you no longer need. I don’t normally recommend software tools, but in this case, the nest way to clear out the clutter is to use CleanMyMac X. It can scan your Mac at the press of a button, identify all the files you don’t need, and allow you to get rid of them with one more click. Here’s how to use it:
- Install, and launch CleanMyMac X — download a free edition here
- Choose Smart Scan from the list of utilities in the sidebar.
- Press Scan.
- When it’s finished, press Run to delete files immediately, or Review Details to see what it has found.
Once you’ve cleared out the clutter, you can go ahead and create your bootable installer. Here’s how:
- Launch the App Store app and search for macOS Catalina. (If you’re reading this before Catalina has been launched, you’ll need to use the public beta. You can sign up for Apple’s public beta program and download it here Apple Beta Software Program)
- When the results appear, click on Catalina, then click ‘Get’.
- Wait for it to download. When it’s finished, the installer will launch. Quit it immediately.
The installer has now been saved in your Applications folder. You can go ahead and check, if you like. You now have two options for creating the installer. If you’re comfortable with using Terminal, you can go ahead and jump to the instructions for that, below. If you’d rather not use Terminal, there’s a neat utility called Diskmaker X that will do it for you. All you need to do is download and install it and then, when you run it, point it to the macOS Catalina installer you just downloaded. There are full instructions on the download page.
Mac Catalina Bootable Usb
How to create a bootable installer using Terminal
- Plug the USB stick, hard drive or SSD into your Mac.
- Go to Applications>Utilities and double-click Disk Utility to launch it.
- Select the disk you want to use for the installer and choose the Erase tab.
- Choose APFS or Mac OS Extended (Journaled) as the format and choose GUID partition map from the options, if it’s available.
- Give the disk a name and press Erase.
- When it’s finished, quit Disk Utility.
- Go to Applications>Utilities and double-click Terminal to launch it.
- Type:
sudo /Applications/Install macOS Mojave.app/Contents/Resources/createinstallmedia —volume /Volumes/Untitledwhere ‘Untitled’ is the name of your USB stick or external hard drive
- Press Return and wait for the word Done to appear in Terminal.
- Quit Terminal
You now have a macOS Catalina installer on an external disk or USB stick. Eject it, unplug it and keep it safe. You can use it to install Catalina on any Mac that supports it.
One more step: update applications
Once you’ve used tour new installer to install Catalina on a Mac, it’s a good idea to update all your applications so that that are Catalina compatible. You can do this manually, from the App Store and by launching non-App Store apps and choosing check for updates, but that’s a long and tedious process. It’s much quicker and easier to use the updates in CleanMyMac X. Here’s how you do it.
- Launch CleanMyMac X.
- Select the Updater tool in the Applications section.
- Press Select All.
- Press Update.
And that’s it. You’re done. CleanMyMac X checks all your installed apps for updates and then updates them all.
Creating a bootable installer for macOS Catalina isn’t difficult. If you have a spare disk or USB stick and are comfortable using Terminal, you can do it right away. If you’d rather not use Terminal, use the Diskmaker X tool described above. Whichever method you use, make sure you use CleanMyMac X to clear out the junk on your Mac before you start, and use it again to update your applications when you’ve finished.
If you want to use your USB stick with an Apple Mac, you will need to restart or power-on the Mac with the USB stick inserted while the Option/alt (⌥) key is pressed. This will launch Apple’s ‘Startup Manager’ which shows bootable devices connected to the machine. Your USB stick should appear as gold/yellow and labelled ‘EFI Boot’. How to create a bootable macOS Big Sur USB install drive. Step 1: Download macOS Big Sur. After Big Sur launches later this year, you’ll be able to download it directly from the Mac App Store.
It does not matter whether you use macOS or Windows 10. It’s just a matter of time until your device will refuse to start, which could happen for many reasons, including (and not limited to) file corruption, hardware failure, and buggy update. If the unexpected happens with an Apple computer, you can use a macOS bootable USB with the installation media to repair it.
Create Bootable Usb On Mac From Iso
This is one of the main reasons you should consider making a macOS bootable USB when your device is working properly. However, if none of your devices (MacBook, MacBook Air, MacBook Pro, iMac, Mac Pro, or Mac Mini) aren’t working when you need them the most, then you can use a PC to rescue your Apple device. You can use a Windows 10, Windows 8.1, or Windows 7 device to quickly create a USB bootable installation media to reinstall macOS Catalina or Big Sur on your Mac.
In this guide, you’ll learn the steps to create a macOS Catalina bootable USB installation on Windows 10, which you can use to reinstall or upgrade the Apple OS.
Requirements
Before proceeding, you’ll need the following:
- Broken Mac computer running macOS (version 10.12, 11, or later).
- A trial copy of the TransMac software.
- One high-quality USB flash drive with 16GB of storage.
- Copy of macOS (DMG file).
Create macOS bootable USB installation media
To create a bootable USB drive with macOS, use these steps:
Download and install TransMac on the Windows 10 device.
Quick note: This is a paid software, but it gives you a 15-day trial, which is more than enough time. (If this works for you and you want to support the developer, you can purchase the full version.)Connect the USB flash drive. (If you have any data on the flash drive, remember to make a backup, as everything on it will be erased.)
Right-click the TransMac app and select the Run as administrator option.
Click the Run button. (If you’re using the trial version, wait 15 seconds.)
Right-click the USB flash drive, select the Format Disk for Mac option from the left navigation pane.
Quick note: You want to do this before creating the bootable media because there is a good chance that the drive was formatted using a Windows device. If this is the case, the chances are that it’s using an MBR partition, and the USB drive needs a GPT partition to work on a Mac.Click the Yes button to format the drive on the warning message.
Confirm a name for the drive. For example, “macOS bootable USB.”
Click the OK button.
Click the Yes button.
Click the OK button.
Right-click the USB flash drive and select the Restore with Disk Image option from the left navigation pane.
Click the Yes button to confirm the erase of the USB flash drive data.
Click the browse button on the right.
Select the .dmg file with the macOS installation files.
Click the Open button.
Click the OK button.
Click the Yes button.
Once you complete the steps, you can now insert the USB flash drive on your Mac computer to install, reinstall, or upgrade the operating system to the latest macOS version, which can be Sierra, Catalina, Big Sur, or higher.
Create a GPT partition on USB flash drive
If the USB flash drive is not working with TransMac, it could still be a partition problem. In this case, you may need to redo the entire process again. However, this time you should use the following steps to use the Diskpart command-line utility on Windows 10 to create the appropriate GPT partition, and then follow the above instructions.
To create a GPT partition on a removable drive, use these steps:
Open Start.
Search for Command Prompt, right-click the top result, and select the Run as an administrator option.
Type the
diskpartcommand and press Enter.Enter the
list diskcommand to view all drives connected to your computer and press Enter.Type the
select diskcommand followed the number assigned for the USB flash drive (for example,select disk 4), and press Enter.Enter the
cleancommand and press Enter.Type the
convert GPTcommand and press Enter.Enter the
create partition primarycommand and press Enter to complete the process.
Once you formatted the USB flash drive with a GPT partition, you can use the instructions mentioned above to use TransMac to create a bootable media, but this time skip steps No. 5 through 10 and continue on step 11.
After the process completes, which can take up to an hour, connect the USB flash drive and power on your Mac holding down the Option key, select the USB drive to begin installing macOS.
If you have problems creating the bootable media, you can get a USB flash drive that comes with macOS Sierra, El Capitan, Catalina, etc., on it with the link mentioned below. (I haven’t tried it personally, but it’s worth the try if nothing works.)
If your Mac suddenly refuses to boot up properly, you might need a bootable macOS USB installer to make repairs. But how do you create such a disk if all you're left with is a Windows 10 computer? Fortunately, there's a great tool that you can use for free to create bootable macOS media on a USB drive in a Windows 10 environment. This article shows you how to download a macOS DMG file, format a USB drive using a GUID Partition Table, burn the DMG to the drive and boot your Mac from the USB. All the steps except the last one are done on a Windows 10 machine.
Part 1: Download macOS or Mac OS X DMG File
The first step is to get the DMG disk image file for the version of macOS that you want. You can get a copy of the latest macOS version from Apple download portal or App Store here. There are also several other direct download sites that offer various versions of Mac OS X in DMG format rather than the standard APP format that runs on Mac. Since you're working in a Windows environment, you need the DMG rather than the APP file.
macOS DMG Download Link:
Part 2: Format USB Drive to GPT (Optional)
Updates (Dec 8, 2020): The latest version of UUByte DMG Editor is able to format the USB automatically, so this part is optional. Follow the steps only when the burning process failed in Part 3.
Create Bootable Usb On Mac Disk Utility
Mostly, the USB drive was formmated to FAT32 in default when being shipped out from the factory. However, FAT32 can be only used for installing OS with legacy BISO, which doesn't work for macOS. So the next step is to format your USB drive in the GPT partition style in order to burn installation files to the desired USB drive. You can do this in Command Prompt as admin. In elevated Command Prompt (Ctrl+Shift+Enter), input the following series of commands followed by Enter after each line:
Diskpart
List disk
Select Disk X (X stands for the USB drive name that appears after the previous command)
Clean
Convert GPT
Create partition primary
Part 3: Create Bootable macOS USB from Windows 10/8/7 PC
You have now formatted the partition of USB drive. It's time to download UUByte DMG Editor for Windows. Although this is a premium software, you can use the initial free trial period to create a bootable macOS USB on Windows 10. After installing the application, follow the sequence of steps shown below:
Create Bootable Usb On Mac For Windows
Step 1: Right-click the software icon on desktop and select 'Run as Administrator' from the contextual menu. Choose 'Run' when prompted.
Step 2: Insert your formatted USB drive, and click 'Burn' tab on the main screen.
Step 3: Click 'Browse' button to import macOS dmg file into the program. And select the USB drive name from the second row. You can also set a volume labe for that USB drive.
Step 4: Click 'Burn' button at the bottom to start the process. You will see a progress bar and wait around 10 minutes to get it done.
Step 5: Once the progress bar is at 100%, a bootable macOS USB is ready. After that, you can use that USB drive for installing macOS.
This is one of the easiest way to create a bootable macOS USB on a Windows PC. The steps are simple and instructions are pretty clear.
Mac Os Catalina Bootable Usb Install Drive
Part 4: Boot Mac from macOS USB Drive for Installation
Now remove the USB drive and insert it into the Mac computer. To boot from the disk, you need to hold down the option key when you hear the boot chime. This will take you to the Startup Disk Manager, where you should be able to see the USB drive. It might have a different name, but as long as it is bootable, you'll be able to see it there. Once you select it, the computer will boot from the disk and the macOS installation will begin.
Conclusion:
Create Bootable Usb On Macos Catalina
The whole process might look a bit complicated if this is your first time, but just follow the instructions in this article and you should be fine. That being said, you need to be careful when downloading the DMG file and formatting your USB drive. If you don't do these two steps correctly, the output drive from the UUByte DMG Editor software won't be bootable, which means you can't install macOS from that USB drive, and you may need to do the whole thing over again.