To upgrade from OS X Mountain Lion, first upgrade to OS X El Capitan, then upgrade to macOS Big Sur. Make a backup Before installing any upgrade, it’s a good idea to back up your Mac. Carbon Copy Cloner 4.1.24 is compatible with Mountain Lion (10.8), Mavericks (10.9), Yosemite (10.10), El Capitan(10.11), Sierra (10.12) and High Sierra (10.13). Note that while this version of CCC may work on El Capitan and newer OSes, we recommend that El Capitan+ users upgrade to CCC 5. It arrived in OS X Mountain Lion in 2012, but actually that replaced iChat, which was the messaging app that had existed on the Mac since 2002. Primarily what macOS 11 Big Sur will bring to. Or you can get the latest macOS Catalina on the App Store for other versions including High Sierra (10.13), Sierra (10.12) or El Capitan (10.11). If you’re using Lion (10.7) or Mountain Lion (10.8), you will need to upgrade to El Capitan (10.11) first before you could upgrade to macOS Catalina.
- How To Upgrade From Mountain Lion To Catalina
- Upgrade From Mountain Lion To Catalina
- Can You Upgrade From Mountain Lion To Mojave
- Can You Upgrade From Mountain Lion To Catalina
- Upgrade From Mountain Lion To Catalina
Upgrade to macOS Big Sur
How To Upgrade From Mountain Lion To Catalina
Before installing this upgrade, make sure that your Mac is ready.
Check compatibility
macOS Big Sur supports most Mac models introduced in 2013 and later.
View compatible Mac modelsMake a backup
Before you upgrade, make a complete backup with Time Machine, or store your files in iCloud.
Learn how to back up your MacFree up space
If the installer needs more storage space to upgrade, you can free up space using tools that come with your Mac.
Free up storage spaceDownload macOS Big Sur
If you’re using macOS Mojave or later, choose Apple menu > System Preferences, then click Software Update. If you’re using an earlier macOS, use the App Store instead.
Learn how to download and install macOS Big SurGo to the App StoreGet to know macOS Big Sur
Learn about some of the new features of macOS Big Sur.
Control Center
Control Center brings favorite controls such as Bluetooth, Wi-Fi, Do Not Disturb, and Sound together in a single place—so you can easily adjust them at any time.
Use Control CenterNotification Center
Notification Center puts notifications and>
Safari
Customize your start page, navigate with ease using the new tab bar, and access a new privacy report to see just how Safari protects your privacy as you browse.
Get to know SafariMaps
Discover great places around the world and navigate easier with guides, cycling directions, indoor maps, Look Around, electric vehicle routing, and more.
Messages
Send messages to friends and family using new tools that make it easier to keep track of group conversations and give you fun, engaging ways to express yourself.
Use MessagesLearn more on YouTubePhotos
Use the expanded editing capabilities in Photos to easily make simple changes and more advanced adjustments to your photos.
Learn how to edit your photosUpgrade From Mountain Lion To Catalina
Have a question?
Ask everyone. Our Apple Support Community can help you find answers.
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Get supportmacOS Big Sur elevates the most advanced desktop operating system in the world to a new level of power and beauty. Experience Mac to the fullest with a refined new design. Enjoy the biggest Safari update ever. Discover new features for Maps and Messages. And get even more transparency around your privacy.
Check compatibility
macOS Big Sur is compatible with these computers:
MacBook introduced in 2015 or later
MacBook Air introduced in 2013 or later
MacBook Pro introduced in late 2013 or later
Mac mini introduced in 2014 or later
iMac introduced in 2014 or later
iMac Pro
Mac Pro introduced in 2013 or later
View the complete list of compatible computers.
If upgrading from macOS Sierra or later, macOS Big Sur requires 35.5GB of available storage to upgrade. If upgrading from an earlier release, macOS Big Sur requires up to 44.5GB of available storage. To upgrade from OS X Mountain Lion, first upgrade to OS X El Capitan, then upgrade to macOS Big Sur.
Make a backup
Before installing any upgrade, 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.
Get connected
It takes time to download and install macOS, so make sure that you have a reliable Internet connection. If you're using a Mac notebook computer, plug it into AC power.
Download macOS Big Sur
If you're using macOS Mojave or later, get macOS Big Sur via Software Update: Choose Apple menu > System Preferences, then click Software Update.
Or use this link to open the macOS Big Sur page on the App Store: Get macOS Big Sur. Then click the Get button or iCloud download icon.
Begin installation
After downloading, the installer opens automatically.
Click Continue and follow the onscreen instructions. You might find it 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.
Allow installation to complete
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 both macOS and related updates to your Mac firmware.
Stay up to date
After installing macOS Big Sur, you will be notified when updates to macOS Big Sur are available. You can also use Software Update to check for updates: Choose Apple menu > System Preferences, then click Software Update.
Can You Upgrade From Mountain Lion To Mojave
Or get macOS Big Sur automatically
Can You Upgrade From Mountain Lion To Catalina
If you're using OS X El Capitan v10.11.5 or later and your App Store preferences or Software Update preferences are set to download new updates when available, macOS Big Sur will download conveniently in the background, making it even easier to upgrade. A notification will inform you when macOS Big Sur is ready to be installed. Click Install to get started, or dismiss the notification to install later. When you're ready to install, just open the file named Install macOS Big Sur from your Applications folder.
Learn more
Upgrade From Mountain Lion To Catalina
- If the installer shows a list of apps that are not optimized for your Mac, learn about 32-bit app compatibility, then choose whether to proceed with the installation.
- For the strongest security and latest features, upgrade to macOS Big Sur. If you have hardware or software that isn't compatible with Big Sur, you might be able to install an earlier macOS.
- You can also 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.