How to clean install macOS Catalina from Bootable USB Drive

Discover how to clean install macOS Catalina on your MacBook from a Bootable USB Drive.
Part 2 - Bootable USB-Stick ➜ (1:56min)
Part 3 - Fresh Install ➜ (7:41min)
Part 4 - Summary ➜ (16:26min)

# Tutorial Series # Used MacBook - Still Worth It?

First, we will need to download a copy of Catalina from the App Store, and after doing so the installer will show up in your Applications folder as “Install macOS Catalina”.

But instead of just running the installer, we hit quit and create a bootable USB stick, for this we go to:
➜ Applications ➜ Utilities ➜ Terminal

There you can copy and paste the command from the Apple support article, make sure to replace the last part called “MyVolume” with the name of your USB stick.

If you are unsure, an easy way to check is to start the Disk Utility, if you go to View and select show all devices it will be easy to double-check the name of your USB drive.

After you created the Bootable USB drive installer, please be aware that newer MacBooks have a so-called T2 security chip. While in the past on older models you could just plug in any USB stick or external drive and boot from it, the new security chip will prevent it unless you previously change the settings.

Chase A - Older Mac Computers:
1. On Startup Press ➜ Option (⌥)
2. Select macOS Catalina ➜ Boot from USB

Chase B - Newer Mac Computers:
1. Startup Press ➜ Command (⌘)-R:
2. Go to ➜ Utilities ➜ Startup Security Tool
3. Startup Press ➜ Option (⌥)
4. Select macOS Catalina ➜ Boot from USB

Chase C - Latest Apple Silicon:
1. Press and hold the power button until you see the startup options window.
2. Select ➜ macOS Recovery ➜ Utilities ➜ Startup Security Tool
3. Press and hold the power button until you see the startup options window.
4. Select macOS Big Sur ➜ Boot from USB

As you can see, because Apple has beefed up security with this new chip, there is one additional step required. If you are coming from an older model it used to be much easier.

Keep in mind that most users just download and install straight from the App Store, but for computer enthusiasts or system administrators having a USB install media is usually popular.

That's pretty much it, if you have come that far, installation should be easy.

#ReviewTechTV

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// This video does not include product placement. I got the product myself. //

[ReviewTechTV]

UPDATE - Fresh Install (macOS Big Sur)

[drgasparks]

Thank you, thank you, thank you:) Without going into details....money is rather tight right now. My wife, who is a heavy end graphics user, mostly the Adobe Suite, really needed a new computer. Her 2012 MacBook Pro was running slow it was painful to even watch. I just finished upgraded her to 16gm Ram and put in a 1T SSD card. As you showed, I created a Catalina USB Boot Disk. I also recorded before and after time test. Before the upgrade it took 2:34 to boot up. After the upgrade, :27 seconds. Her disks speed went from 31.8 Write/26.3 Read to 398.9 Write/438.6 Read. All of this was done for about $160:) I've watched about a dozen different videos on how to do this and yours by far was the most informative and helpful. So thank you once again:)

[aeoniannox]

You're a savior!! I was panicking because I erased my hard drive since I have to sell it but I was unable to reinstall macOS no matter how many times I tried even in Internet Recovery (I even followed whatever tips I found but it was useless too). Your tutorial saved me from doom!! THANK YOU SO MUCH!!

[itguybd]

thank you for this... I spent a solid 10 minutes trying to figure out what apple changed, an why i couldnt get past this security. I owe you a dono or something for your time on this man. saved me ten more minutes of getting frustrated at work.

[IGOTNOSBOI]

Quick note if you guys want to install Mac OS on a portable usb drive you have to partion it first leave at least 12 gb for the “install Mac OS” and the rest for the actual Os

[ahmedjebreen]

Hello...
I have MacBook Pro 2018 15" with macos High Sierra.
I've tried this and unable to install the Catalina. Always directed me to High Sierra!


Is there any advice?


Thanks in advance ...

[ВиталийОвчаренко-ин]

To clean install macOS Catalina from a bootable USB drive, follow these steps:

1. First, create a bootable USB drive containing macOS Catalina by following Apple's official instructions.
2. Connect the bootable USB drive to your Mac and restart the computer.
3. Press and hold the "Command + R" keys during startup to enter Recovery Mode.
4. In Recovery Mode, navigate to the "Disk Utility" option and select it.
5. Choose your Mac's main hard drive from the list of available disks and click "Erase." Format it as Mac OS Extended (Journaled).
6. Quit Disk Utility and go to the "Reinstall macOS" option.
7. Choose the hard drive you erased earlier and follow the installation prompts.
8. Once the installation is complete, your Mac will restart with the freshly installed macOS Catalina.

[Senkii]

U failed to mention (for the older models) that u need to format the drive to MacOS (Journaled).

[kicle]

Thanks. I got it. How I have another problem during the build of the bootable Catalina USB. I am using a Mac Mini with Big Sur OS. I have got the error of '... the version you want to open is too old' during the opening of the Catalina.app file. Also the terminal command (to install the OS for this) is not working. I suspect, the Big Sur has block the operation. I am new to MAC platform, if you know how to get over this, please let me know.
It looks like if you can us a older OS (before big sur) you can do it, ie I have seen several demo in YT channel using old iOS before Big Sur.

[One-Crazy-Cat]

It will be slow to re-image as you’re coming from a compressed installer into a full image and verifying the data integrity as it goes so it’s more work than actually installing the OS.

[Takussaagut]

Creat and thank you. Just wanted to add this info: in your case find my mac (my my iDevice) not turned on with earlier owner/user. That's why you didn't face iCloud activation lock (also known as hello screen), otherwise you wouldn't be able to fresh install this OS as you showed on this video. Creat video and explain. Thank you.

[MohammadSalah]

Amazing explanation because I have MacBook Pro 16 i have this problem cannot boot from usb

[VRJacky]

does this work if you have catalina installed already? im upgrading the HDD to an SSD

[MacfadYT]

Am I supposed to install the OS Catalina in my USB or it doesnt matter?

[AbodLive]

could you please share with me some direct links to download the macos Catalina 10.15.7 not from appstore

[SonnyHung]

@ReviewTechTV - What Mac laptop model did you do use to create the USB Installer for Catalina?

[temario]

i´m downgrading from big sur to catalina, and my disk is not appearing as destination install, only appears the bootable usb. I tried to format the ssd but utility disk it doesn't let me either, so frustrating. thanks.

[rhettshipley]

Can you use a hard drive in place of a usb drive? And then boot from the hard drive?

[petezaparti]

I created the bootable usb, however when I click the installer on the start up, it just brings up an image of a circle with a line crossed out. Please help.

[lazyninja]

Hello can I download the Mac os on my android phone and then shift in usb and later on flash it in my MacBook air 2012 ?