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.
It installs an app named Install Version Name. Open that app from your Applications folder to start 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 10.10 can upgrade.
Check compatibility
If a macOS installer can't be used on your Mac, the installer will let you know. For example, it may 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.
- @katemor Its not true that App Store no longer has El Capitan as download. It does not have it as download, if your Apple-ID has never registered a machine with El Capitan. It does not have it as download, if your Apple-ID has never registered a machine with El Capitan.
- OS X Yosemite (/ j oʊ ˈ s ɛ m ɪ t i / yoh-SEM-it-ee; version 10.10) is the eleventh major release of macOS, Apple Inc.' S desktop and server operating system for Macintosh computers. OS X Yosemite was announced and released to developers on June 2, 2014, at WWDC 2014 and released to public beta testers on July 24, 2014.
- Mac App Store was launched on January 6, 2011, as part of the free Mac OS X 10.6.6 update for all current Snow Leopard users. After 24 hours of release, Apple announced that there were over one million downloads. On June 4, 2018, Apple announced that a new version of the App Store would be included in macOS Mojave.
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. Find out how to back up your Mac.
Download macOS
It takes time to download and install macOS, so make sure 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 being downloaded from the App Store, the installer opens 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 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 start 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 may be easiest to start the installation in the evening so that it can be completed 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 the installation to finish without putting your Mac to sleep or closing its lid. Your Mac may restart, show a progress bar or show a blank screen several times while macOS and related firmware updates are being installed.
Os X El Capitan App Store Link
Learn more
Does Apple Still Support Os X El Capitan
You may 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.