Update Mac High Sierra

macOS Catalina was the newest operating system by Apple until macOS Big Sur succeeded it in 2020. If your Mac still runs Mojave or an even older macOS version, you'll be amazed by all the new features and improvements in Catalina. So here’s how to upgrade to macOS Catalina.

First, clear out the junk

When you do a regular upgrade, the installer replaces some files on your Mac with others, but leaves most untouched. That means that all the system junk your Mac has accumulated over the years stays there. And as you upgrade year after year, you accumulate more and more. As you can imagine, upgrading your operating system on a junk-filled Mac is rather like putting one layer of wallpaper on top of another — eventually you have to scrape it off and start again.

Likewise, it’s always a good idea to clear out the clutter before you upgrade. My recommendation, after years of experience upgrading Macs, is that you use CleanMyMac X. It’s very quick and easy to use and will get rid of clutter, making your Mac run more smoothly and freeing up tens of gigabytes of disk space. You can either let it decide what to remove or go through its scan results yourself and decide what to trash and what to keep.

Before you upgrade, we recommend that you back up your Mac. If your Mac is running OS X Mavericks 10.9 or later, you can upgrade directly to macOS Big Sur. You’ll need the following: OS X 10.9 or later; 4GB of memory; 35.5GB of available storage on macOS Sierra or later. Some features require an Apple ID; terms apply. Hi all, I've been a bit lazy with updating my Macbook Pro OS, I'm still on 10.13.6. It doesn't look like I can jump straight to 10.15 - do I need to update 10.13.6 to something else before I can get it to 10.15? Make sure you have at least 14.3GB of available storage and 2GB of memory on your Mac. If you are going to update macOS to High Sierra on MacBook series, don’t forget to plug it into AC power. Internet Connection. Some macOS update issues occur due to the Internet connection that is slow or unstable.

Then, backup your Mac

As you will see below, there are a couple of different ways you can upgrade to Catalina, but before you decide, and certainly before you upgrade, you should make a full backup of your current Mac setup. Upgrading one OS on top of another carries very few risks, but they are not non-existent so be safe now rather than sorry later. If you use Time Machine you can make a backup with that. But the best idea is to make a complete bootable clone of your current startup disk on an external drive.

To clean install or not to clean install

Remember I said you had a couple of options for upgrading? Here they are:

Regular install
Clean install

A regular install places Catalina files on your startup disk over the top of whatever OS you’re currently running. It doesn’t overwrite anything else. So all your applications, documents, settings, photos, movies, and music stay where they are. Unfortunately, all the junk files your Mac has accumulated also remain there. This option is quicker in the short-term, but your Mac won’t run as smoothly in the long-term. If you choose this option, I’d definitely recommend you use CleanMyMac X to clear out the clutter, before you upgrade.

A clean install erases your startup disk completely and then installs macOS Catalina on a completely clean disk. It takes longer, but in the long run your Mac will run more quickly and more smoothly. You will have to clone your startup disk before you start, and then spend time reinstalling applications and setting them up afterwards, however.

How to do a regular install of macOS Catalina

Check that your Mac can run Catalina. Here’s the list of compatible Macs:

MacBook 2015 and later

MacBook Air 2012 and later

MacBook Pro 2012 and later

IMac 2012 and later

IMac Pro 2017 and later

Mac Pro 2013 and later

2. Make sure you’re connected to the internet and have a reliable connection. If you’re using a MacBook, MacBook Air, or MacBook Pro, plug it into mains power.

3. Launch the App Store app on your Mac and search for 'macOS Catalina.'

4. When you find it, click 'Get.'

5. Wait for Catalina to download and when it’s ready to install, click Continue. Type in your admin username and password, if necessary.

6. Wait for Catalina to install. Your Mac will restart several times and it may take a while, so be patient! If you are using a laptop, don’t close the lid.

7. Once it has finished installing, you can continue to use your Mac as normal.

How to clean install macOS Catalina

We have covered clean installing Catalina in more detail in this article How to Clean Install macOS Catalina but here’s a summary.

Make a full bootable clone of your Mac, just in case the worst happens.
Grab a USB stick that’s at least 16GB capacity, or an external hard drive or USB stick.
Erase and re-format the USB stick or external disk.
Create a bootable installer on the disk.
Boot from the new install disk and use Disk Utility in macOS Utilities to erase your startup disk.
Go back to macOS Utilities and choose install macOS, with your startup disk as the location for the install.

Once it’s finished, set up your Mac, reinstall applications and restore your settings.

My apps are slow or stopped working on macOS Catalina

Okay, you’ve successfully installed macOS 10.15 Catalina. But some of your apps are no longer available. That’s a heavy blow from macOS Catalina as it no longer supports 32-bit apps. According to Apple, 64-bit apps are more memory-efficient than 32-bit ones. But for most of us it means we will lose many favorite games and applications, including Photoshop CS. To minimize the damage, you should first check how many 32-bit apps you have. It's possible to do with the same Mac maintenance app we've mentioned above.

Run CleanMyMac X — you can download a free edition here.
Click the Uninstaller tab.
Now, by clicking on the 32-bit tab, you will see the list of 32-bit apps on your Mac.

Next up, click the Updater tab.
Here you can update your 32-apps (and all the rest of apps) to newer versions. Many developers have already optimized their software for 64-bit architecture. With this method you’ll update all your software in one-go to make it Catalina-friendly. As you can see, I can update 17 apps with just one button.

Thanks for reading this article. Hope you will like it on Catalina!