Primarily what macOS 11 Big Sur will bring to you if you upgrade from Catalina is a design refresh, Control Centre, a revamped Notification Centre, and a new version of Messages. Yosemite - OS 10.10.x El Capitan - OS 10.11 Sierra - OS 10.12 High Sierra - OS 10.13 Third, you need to be concerned about any third party software you are using, and most likely, will need either to upgrade some/most/all of them to be compatible with the OS you want to move to, or possibly some of them might not work at all. Learn how to set up and use macOS. Find all the topics, resources, and contact options you need for macOS.

The classic OS X 10.12, or rather macOS upgrade, introduced tons of features anyone would still want on their Mac. Why? Because, it's well-tested and secure. Now we'll take a quick look at the legendary macOS Sierra upgrade. (In case you want to upgrade your Mac to macOS 10.13 High Sierra, check out this guide.)

Interestingly, it first brought Siri to your Mac. This is great news for everyone who’s already used to her help on iOS. Then, there’s Watch unlocking for Mac, there’s one-click Apple Pay, tabs in apps, and cross-device copypasting. Just to name a few.

So, if you were on the fence about upgrading to Sierra, and in fact, any newer OS, go right ahead. Your Mac deserves a refreshment.

Safari automatically keeps an eye out for any saved passwords that may have been involved in a data breach. Using advanced cryptographic techniques, Safari periodically checks a derivation of your passwords against an updated list of compromised credentials. If a breach is discovered, Safari helps you upgrade your existing passwords. Does order matter when you upgrade macOS? If your current operating system is OS X Lion (10.7), you can skip a few versions, and upgrade directly to macOS High Sierra. To upgrade to Sierra from, say, Mavericks, you’ll have to consequently upgrade to Yosemite and then to El Capitan first. Check Your macOS for Sierra Compatibility.

How to upgrade macOS: Sierra 10.12 compatibility list

As with the previous versions, macOS Sierra is available for a limited list of Mac models.
Here are the models of Macs that are compatible with macOS 10.12 and can upgrade to Sierra:

Does order matter when you upgrade macOS?

If your current operating system is OS X Lion (10.7), you can skip a few versions, and upgrade directly to macOS High Sierra. To upgrade to Sierra from, say, Mavericks, you’ll have to consequently upgrade to Yosemite and then to El Capitan first.

Check Your macOS for Sierra Compatibility

These OS versions can upgrade to Sierra:

• OS X Mountain Lion v10.8
• OS X Mavericks v10.9
• OS X Yosemite v10.10
• OS X El Capitan v10.11

Here’s how to find out which OS version you’re running now:

1. Click Apple icon in the top left corner.
2. Choose About this Mac.
3. There you have it, in capital letters.

Memory (RAM): 2 GB (preferably 4 GB)
Sierra is pretty lightweight, so you only need 2 GB of RAM to upgrade. Cool, eh?

Disk space: 8 GB of free space on drive.
In the same About this Mac menu select 'Storage' tab. In front of the multi-colored bar, you will see the phrase, 'X.XX GB free out of XX.XX GB.' If you don't have at least 8 GB of free space, you should delete some old files.

Before you update macOS, don’t forget to:

Clean up your Mac

This is essential if you want a fast and effortless update, and glitchless work of your new macOS. And it’s also pretty easy. To give your Mac a cleanup, you need to get rid of system junk, uninstall extra apps, and clean some old caches. If that sounds like a lot of work, you can get a Mac cleaner like CleanMyMac for the job.

How to update your Mac: Clean it up first

1. Launch it.
2. Hit Scan to find all the extra files you can delete.
3. Press Run.

As you can see, I have 8.56 GB worth of caches, obsolete language files, broken downloads. You'll feel great getting rid of them.
That will give your Mac a basic system cleanup, but CleanMyMac is going to come in handy after the update as well. It monitors your Mac’s health, helps you speed up the system and remove unnecessary apps (Trashing doesn’t fully uninstall apps, by the way).

Back up your Mac

This is basic common sense before any Mac software update you’d like to undertake. Why? Well, because sometimes updates happen less smoothly than you’d like them to. To make sure you have all your information and files saved up neatly, you need a backup. To back up your Mac, you need to activate Time Machine.

• Open your Applications folder.
• Choose Time Machine.
• 'Select Backup Disk…'
  Note: You may need to first choose to 'Set Up Time Machine.'
• Choose where you'd like to store your backup.
• Both an external drive or an Airport Time Capsule fit.

• Switch the toggle on the left, from 'OFF' to 'ON.' Right beneath the name of your storage device, you'll see 'Oldest backup,' 'Latest backup,' and 'Next backup' — Your backup will begin within 5 minutes. To speed it up, click the arrow clock icon next to the Date & Time at the top-right of the menu bar and select 'Back Up Now.'

How to download macOS Sierra (or newer macOS) and install it

macOS Sierra is increasingly becoming a relic. Since 2020, the newest available macOS version is Big Sur. But it all comes down to hardware. Your Mac can only upgrade to the latest version its hardware can support. If your Mac is from around 2012 it can update as high up as to macOS Catalina. If your Mac is from 2010 or older, its limit is macOS High Sierra.

To download any new macOS and install it you’ll need to do the next:
1. Open System Preferences... in the  Apple menu.
2. Click on Software Updates.
On top of the list you'll see the latest macOS version your Mac can download. In our case, it's macOS Big Sur.

Can I Upgrade To Catalina From Yosemite

Another way to do it is via the Mac App Store.

1. Open App Store.
2. Click the Updates tab.
3. You’ll see macOS updates available for your Mac.
4. Click Update.

Wait for macOS download and installation. Your Mac will restart when it’s done.

Now you have a new OS.
For historic interest, this is how macOS Sierra looked back then when it was still available in the Mac App Store. Now, it can't be found there anymore.

Download macOS installers directly from Apple

For users of past operating systems Apple created a handy a list of macOS installers. They go as far back as to macOS Yosemite. The first 3 of them will open and start the update process automatically.

• macOS High Sierra 10.13
  The 3 following installers will download macOS as a disk image (.dmg) After you unpack it, the macOS updater app will appear in your Applications.

We hope this guide has been of use, and don’t forget to clean up your Mac and back it up before you get the classic macOS! Cheers.

To get the latest features and maintain the security, stability, compatibility, and performance of your Mac, it's important to keep your software up to date. Apple recommends that you always use the latest macOS that is compatible with your Mac.

Learn how to upgrade to macOS Big Sur, the latest version of macOS.

Check compatibility

If a macOS installer can't be used on your Mac, the installer will let you know. For example, it might say that it's too old to be opened on this version of macOS, or that your Mac doesn't have enough free storage space for the installation.

To confirm compatibility before downloading, check the minimum requirements for macOS Catalina, Mojave, High Sierra, Sierra, El Capitan, or Yosemite. You can also find compatibility information on the product-ID page for MacBook Pro, MacBook Air, MacBook, iMac, Mac mini, or Mac Pro.

Make a backup

Before installing, it’s a good idea to back up your Mac. Time Machine makes it simple, and other backup methods are also available. Learn how to back up your Mac.

Download macOS

It takes time to download and install macOS, so make sure that you're plugged into AC power and have a reliable internet connection.

Safari uses these links to find the old installers in the App Store. After downloading from the App Store, the installer opens automatically.

• macOS Catalina 10.15 can upgrade Mojave, High Sierra, Sierra, El Capitan, Yosemite, Mavericks
• macOS Mojave 10.14 can upgrade High Sierra, Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion
• macOS High Sierra 10.13 can upgrade Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion

Can I Upgrade To Catalina From Yosemite

Safari downloads the following older installers as a disk image named InstallOS.dmg or InstallMacOSX.dmg. Open the disk image, then open the .pkg installer inside the disk image. It installs an app named Install [Version Name]. Open that app from your Applications folder to begin installing the operating system.

• macOS Sierra 10.12 can upgrade El Capitan, Yosemite, Mavericks, Mountain Lion, or Lion
• OS X El Capitan 10.11 can upgrade Yosemite, Mavericks, Mountain Lion, Lion, or Snow Leopard
• OS X Yosemite 10.10can upgrade Mavericks, Mountain Lion, Lion, or Snow Leopard

Upgrade To Catalina From Yosemite

Install macOS

Follow the onscreen instructions in the installer. It might be easiest to begin installation in the evening so that it can complete overnight, if needed.

If the installer asks for permission to install a helper tool, enter the administrator name and password that you use to log in to your Mac, then click Add Helper.

Upgrade To Catalina From Yosemite

Please allow installation to complete without putting your Mac to sleep or closing its lid. Your Mac might restart, show a progress bar, or show a blank screen several times as it installs macOS and related firmware updates.

Upgrade To Mojave

Learn more

Can You Upgrade Directly From Yosemite To Catalina

You might also be able to use macOS Recovery to reinstall the macOS you're using now, upgrade to the latest compatible macOS, or install the macOS that came with your Mac.