Operating System OS X Mountain Lion Item Weight 12.5 pounds Product Dimensions 20.8 x 17.7 x 6.9 inches Item Dimensions LxWxH 20.8 x 17.7 x 6.9 inches Color White Processor Brand Intel Processor Count 4 Computer Memory Type DDR3 SDRAM Flash Memory Size 8 Hard Drive Interface ATA Batteries 1 Lithium ion batteries required. MacOS High Sierra is a seasoned, robust, and straightforward-to-use operating system developed for your MacBook. With this OS, some of the novel features have been added for the desktop users. MacOS High Sierra might not offer diverse underlying differences to the user experience, but there are enough quality changes and they would certainly boost the performance of your Mac. Many Mac users who are attempting to download macOS High Sierra from the Mac App Store will find that a small 19 MB version of “Install macOS High Sierra.app” downloads to the /Applications folder of the target Mac, rather than the complete 5.2 GB Installer application for macOS High Sierra. This is annoying because it prevents a single. 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. Fourth, for High Sierra, Apple introduced the APFS file system.
Is your Mac up to date with the latest version of the Mac operating system? Is it using the version required by some product that you want to use with your Mac? Which versions are earlier (older) or later (newer, more recent)? To find out, learn which version is installed now.
If your macOS isn't up to date, you may be able to update to a later version.
Which macOS version is installed?
From the Apple menu in the corner of your screen, choose About This Mac. You should see the macOS name, such as macOS Big Sur, followed by its version number. If you need to know the build number as well, click the version number to see it.
Which macOS version is the latest?
These are all Mac operating systems, starting with the most recent. When a major new macOS is released, it gets a new name, such as macOS Big Sur. As updates that change the macOS version number become available, this article is updated to show the latest version of that macOS.
If your Mac is using an earlier version of any Mac operating system, you should install the latest Apple software updates, which can include important security updates and updates for the apps that are installed by macOS, such as Safari, Books, Messages, Mail, Music, Calendar, and Photos.
| macOS | Latest version |
|---|---|
| macOS Big Sur | 11.2.3 |
| macOS Catalina | 10.15.7 |
| macOS Mojave | 10.14.6 |
| macOS High Sierra | 10.13.6 |
| macOS Sierra | 10.12.6 |
| OS X El Capitan | 10.11.6 |
| OS X Yosemite | 10.10.5 |
| OS X Mavericks | 10.9.5 |
| OS X Mountain Lion | 10.8.5 |
| OS X Lion | 10.7.5 |
| Mac OS X Snow Leopard | 10.6.8 |
| Mac OS X Leopard | 10.5.8 |
| Mac OS X Tiger | 10.4.11 |
| Mac OS X Panther | 10.3.9 |
| Mac OS X Jaguar | 10.2.8 |
| Mac OS X Puma | 10.1.5 |
| Mac OS X Cheetah | 10.0.4 |
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
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
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.
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.
Learn more
How To Upgrade Your Mac From Os X Lion To High Sierra
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.

