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.
Find out how to upgrade to macOS Big Sur, the latest version of macOS.
Process: I created a USB disk with a bootable El Capitan as per this documentation. Plug-in your USB key on a turned-off computer. Start your Mac, press immediately OPTION (aka ALT) Select the Orange icon (aka a USB stick) labelled El Capitan. If it does not detect it after 10 sec and you only see your hard-drive. Open the program called “Install OS X El Capitan” Follow the on-screen instructions. If this program is missing or will not run, then move it to the trash and empty the trash, followed by re-downloading it from the App Store.
Check compatibility
The version of macOS that came with your Mac is the earliest version it can use. For example, if your Mac came with macOS Big Sur, it will not accept installation of macOS Catalina or earlier.
If a macOS can't be used on your Mac, the App Store or installer will let you know. For example, it may say that it's not compatible with this device or it's too old to be opened on this version of macOS. To confirm compatibility before downloading, check the minimum hardware requirements:
- macOS Catalina 10.15 hardware requirements
- macOS Mojave 10.14 hardware requirements
- macOS High Sierra 10.13 hardware requirements
- macOS Sierra 10.12 hardware requirements
- OS X El Capitan 10.11 hardware requirements
- OS X Yosemite 10.10 hardware requirements
Download macOS using Safari on your Mac
Safari uses these links to find the old installers in the App Store. After being downloaded from the App Store, the installer will open automatically.
- macOS Catalina 10.15 can upgrade Mojave, High Sierra, Sierra, El Capitan, Yosemite or Mavericks
- macOS Mojave 10.14 can upgrade High Sierra, Sierra, El Capitan, Yosemite, Mavericks or Mountain Lion
- macOS High Sierra 10.13 can upgrade Sierra, El Capitan, Yosemite, Mavericks or Mountain Lion
Safari will download 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 will install an app named Install [Version Name]. Open that app from your Applications folder to start installing the operating system.
Apple Download El Capitan Installer
- 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