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.
If a macOS installer can't be used on your Mac, the installer will let you know. For example, it might say that your Mac doesn't have enough free storage space for the installation, or that the installer is too old to be opened on this version of macOS.
If you want to check compatibility before downloading the installer, learn about the minimum requirements for macOS Catalina, Mojave, High Sierra, Sierra, El Capitan, or Yosemite. You can also check compatible operating systems on the product-ID page for MacBook Pro, MacBook Air, MacBook, iMac, Mac mini, or Mac Pro.
The app aims to facilitate the determination of HOT by offering a smart, user-friendly and intuitive interface for the entry of all data points that could impact a holdover time. As inputs are completed, corresponding fields update automatically to ensure that HOTs are easily to calculate and accurate. Click Upgrade Now and follow the onscreen instructions to begin your upgrade. If you don’t have broadband access, you can upgrade your Mac at any Apple Store. Upgrading from an older version of macOS? If you’re running High Sierra (10.13), Sierra (10.12), or El Capitan (10.11), upgrade to macOS Catalina from the App Store. In researching the best free apps for the Mac, I started by using Apple's category list. This makes it easier to cover the wide variety of content available. If an app is on the Mac App Store, it is in one of the 21 categories that Apple has listed.
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.
It takes time to download and install macOS, so make sure that you're plugged into AC power and have a reliable internet connection.
These installers from the App Store open automatically after you download them:
Your web browser 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.
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 both macOS and related updates to your Mac firmware.
You might also be able to use 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.