Easy way to Clean Install mac OS Catalina
macOS Catalina is Apple’s shiny new operating system for the Mac and it’s got a ton of great features and improvements. You’re probably keen to get started and install it straight away. Before you do, consider whether you want to install it over the top of your current OS, or as a completely clean install of macOS Catalina. The benefits of the latter are that it will be like a completely new Mac, with all your settings wiped out, and junk files gone. It should make your Mac run faster. The rest of this article will explain how to clean install macOS Catalina.
Before the clean installation of macOS 10.15 Catalina it’s recommended that you first delete junk and dusty files from the current macOS. There are many free and paid tools to clean junk but the quickest option is to run CleanMyMac X. You can expect to free up tens of gigabytes of space, including old apps, and their leftovers.
To be clear, macOS Catalina Download ISO version 10.15 can be downloaded directly from Apple. Most users find that it is in the DMG format and must be converted using a tool like Ampare if you want an ISO image. To save you time and effort, we and some groups we know have already done this for you. Different providers host each download ISO link. Download macOS Catalina 10.15 Installer. It may seem quite simple to download an update for macOS by going to System Preferences Software Update. But, the size of these updates varies based on.
Here’s how it works.
- Download and install CleanMyMac — try a free edition of the app here
- Choose the System Junk tool.
- Press Scan.
- When it’s finished either press Remove to get rid of all the files it recommends, or choose Review to look through what it’s found and decide for yourself what to delete and what to keep.
Backup your Mac
I can’t stress how important this is. You must backup your Mac before you do anything else. You’re going to be erasing your startup drive completely, so you need a complete backup of everything. You can use Time Machine, another backup app, or a cloning tool. Just make sure you have a complete, preferably bootable, copy of your current installation.
You should also make notes of settings for apps you use regularly – screen grabbing them is a good way to do that. And you should make sure you have a copy of any licence codes that you’ll need when you reinstall applications. You can use Apple’s Notes app to make notes, as long as you sync them with iCloud.
Create a bootable installer of macOS Catalina
If you’re reading this after Catalina ships, you can download it from the Mac App Store and then choose Quit when the installation starts. If you’re clean installing the beta (and, by the way, that’s not something I would recommend. It’s much better to create a dual boot system when you run the beta.
- Grab a USB stick with a capacity of at least 16GB, or an external hard drive or USB.
- Go to Applications>Utilities and launch Disk Utility.
- Launch Disk Utilities and Erase the Drive or USB stick, formatting it as Mac OS Extended (Journaled) or APFS and selecting GUID partition map if a selection is available.
- The easiest method for creating a bootable installer is to use DiskMaker X. However, if you’re comfortable using Terminal, you can do it like this:
- Launch Terminal from Applications>Utilities
- Type:
sudo /Applications/Install macOS Catalina Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install macOS Catalina Beta.app
where ‘Untitled’ is the name of your USB stick or external hard drive - Press Return and wait for the word Done to appear in Terminal.
Once you see ‘Done’ in Terminal you can quit it. Your USB stick or external hard drive is now a bootable Catalina installer, so keep it safe. Now, it’s time to clean install macOS Catalina.
How to Clean install macOS Catalina
Now you've made a backup and created a bootable installer, it's time to actually install the new macOS. Follow these easy steps to clean install macOS Catalina on your Mac.
- Plug your USB stick or external hard drive into your Mac, if it’s not plugged in already.
- Restart your Mac while holding down the Option key.
- When you see the options for booting appear on screen, choose the installer disk you just created.
- When you see the macOS Utilities screen appear, choose Disk Utility
- When Disk Utility launches, choose the Eras tab then select your startup volume (probably called Macintosh HD).
- Give your startup disk a name, then choose a format. If you have a recent Mac with an SSD startup disk, select APFS. If you have an older Mac with a mechanical hard drive or Fusion Drive, choose whichever one you want to use.
- Choose Erase.
- When Disk Utility has finished erasing the disk, quit it to return to the macOS Utilities screen.
- Choose Install macOS.
- Press Continue and choose the drive you just erased and re-formatted as the destination.
- MacOS Catalina will start to install.
- When it’s finished, your Mac will restart and it will look like a brand new Mac. Go through the set-up process to set up a user account, add your wifi network, choose a language, and log in to iCloud.
Once you’ve set up your Mac, you can eject the installer disk and remove it. Remember to keep it safe. You can now restore files you backed up earlier from Time Machine or whichever backup tool you used. Remember to restore files and folders individually, don’t, for example, restore your entire user directory otherwise you’ll copy back all the junk files you just got rid of. Reinstall applications and go through them adding license details where necessary. Check that everything works as you expect it to and use the screen shots you made earlier to configure settings.
There are lots of good reasons why you might want to clean install macOS Catalina, but the most important one is that it should make your Mac feel like new and keep it running smoothly. For ultimate Mac refresh you can also download CleanMyMac X and play with its cleanup tools. Getting rid of old junk feels great.
After months of beta testing, Apple has rolled out macOS 10.15 Catalina to public users. You can download and install macOS Catalina if you have a compatible Mac. The macOS Catalina brings tons of new features such as the Apple Arcade, Screen Time, Voice Control, Sidecar, and Find My app. It has also replaced iTunes with three independent apps – Apple Music, Apple Podcasts, and Apple TV.
Is your Mac compatible with macOS Catalina?
Here’s the list of Mac devices compatible with the new software update:
- MacBook (Early 2015 or later)
- MacBook Air (Mid 2012 or later)
- MacBook Pro (Mid 2012 or later)
- Mac mini (Late 2012 or later)
- iMac (Late 2012 or later)
- iMac Pro (2017)
- Mac Pro (Late 2013 or later)
How to clean install the new software update
Download Install Catalina App
Upgrading to macOS 10.15 Catalina is pretty simple. Tap on the Apple icon in the top-left corner of the screen, then go to System Preferences > Software Update to download it. Alternatively, you can download it directly from the Mac App Store.
But sometimes upgrading macOS from the previous version to the latest one is not the best way. You might want to clean install macOS Catalina to give your Mac a fresh start without any issues from the previous installation. Here’s how to clean install macOS Catalina from USB drive:
Download Install Catalina Dmg
Steps to install
Download Catalina Install File
- Take a full backup of all your important data. Save it to the cloud or an external drive
- You have to create a bootable USB drive. Here’s how you can create it. Make sure the USB drive is at least 8GB in size, and nothing else is stored on it
- 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 Recovery
- After a while, you’ll see the macOS Utilities menu on the screen. Select Disk Utility and then Continue
- Check to make sure you’ve selected the main drive of your Mac. Also ensure that the format is set as APFS or Mac OS Extended
- Now click Erase to wipe out the drive
- 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. Also, head over to the Mac App Store and re-install all the apps you want.