The UI is fairly clean (not cluttered). I like OS X 10.11 compared to earlier ones like Mac OS X 10.7, 10.6 down to Tiger 10.4. I skipped Mac OS X 10.8, 10.9 and 10.10 and just upgraded directly from 10.6.8 to 10.11. Plus OS X 10.11 supports latest browsers from Google and Firefox so many websites work well with latest browsers.
macOS Version 10.14 Mojave
Compatible Macs
MacBook (Early 2015 or newer) MacBook Air (Mid 2012 or newer) MacBook Pro (Mid 2012 or newer) Mac mini (Late 2012 or newer) iMac (Late 2012 or newer) iMac Pro (2017) Mac Pro (Late 2013; Mid 2010 and Mid 2012 models with recommended Metal-capable graphics cards)
OS X 10.8 or later
2GB of memory
12.5GB of available storage (OS X El Capitan 10.11.5 or later)*
*Requires up to 18.5 GB of available storage to upgrade from earlier releases.
macOS Version 10.13 High Sierra
Compatible Macs
MacBook (Late 2009 or newer) MacBook Pro (Mid 2010 or newer) MacBook Air (Late 2010 or newer) Mac mini (Mid 2010 or newer) iMac (Late 2009 or newer) Mac Pro (Mid 2010 or newer)
OS X 10.8 or later
2GB of memory
14.3GB of available storage to perform upgrade*
* Upon completion of the upgrade, macOS High Sierra requires approximately 1.5GB more storage.
MacOS Version 10.12 (a.k.a Sierra)
Compatible Macs: MacBook (Late 2009 or newer), MacBook Pro (Mid 2010 or newer), MacBook Air (Late 2010 or newer), Mac mini (Mid 2010 or newer), iMac (Late 2009 or newer), Mac Pro (Mid 2010 or newer)
OS X 10.7.5 or later
2GB of memory
8.8GB of available storage
Mac OS X Version 10.11 (a.k.a El Capitan)
Compatible Macs: iMac (Mid 2007 or newer), MacBook (Late 2008 Aluminum, Early 2009, or newer), MacBook Pro (Mid 2007 or newer), MacBook Air (Late 2008 or newer), Mac mini (Early 2009 or newer), Mac Pro (Early 2008 or newer) Xserve (Early 2009)
Mac OS X Mountain Lion, Lion, or Snow Leopard v10.6.8 already installed
At least 2GB of RAM
At least 8.8 GB of disk space available
Mac OS X Version 10.10 (a.k.a Yosemite)
Compatible Macs: iMac (Mid 2007 or newer), MacBook (Late 2008 Aluminum, Early 2009 or newer), MacBook Pro (Mid 2007 or newer), MacBook Air (Late 2008 or newer), Mac mini (Early 2009 or newer), Mac Pro (Early 2008 or newer), Xserve (Early 2009)
Mac OS X Snow Leopard v10.6.8 or later already installed
At least 2GB of RAM
At least 8GB of disk space available
Mac OS X Version 10.9 (a.k.a. Mavericks)
Compatible Macs: iMac (Mid-2007 or later), MacBook (13-inch Aluminum, 2008 or 13-inch, Early 2009 or later), MacBook Pro (13-inch, Mid-2009 or later), MacBook Pro (15-inch or 17-inch, Mid/Late 2007 or later), MacBook Air (Late 2008 or later), Mac mini (Early 2009 or later), Mac Pro (Early 2008 or later), Xserve (Early 2009)
Mac OS X Mountain Lion, Lion, or Snow Leopard v10.6.8 or later already installed
At least 2GB of RAM
At least 8GB of disk space available
Mac OS X Version 10.8 (a.k.a. Mountain Lion)
Compatible Macs: iMac (Mid 2007 or newer), MacBook (Late 2008 Aluminum, Early 2009 or newer), MacBook Pro (Mid/Late 2007 or newer), MacBook Air (Late 2008 or newer), Mac mini (Early 2009 or newer), Mac Pro (Early 2008 or newer), Xserve (Early 2009)
Mac OS X 10.6.8 or OS X Lion installed
At least 2GB of RAM
At least 8GB of disk space available
Mac OS X Version 10.7 (a.k.a. Lion)
Mac computer with an Intel Core Duo, Core i3, Core i5, Core i7, or Xeon processor
Mac OS X 10.6.6 or later to install via the Mac App Store, an internal or external DVD drive, or install using an OSX Lion USB Thumb Drive
At least 2GB of RAM
At least 7GB of disk space available
If you try to start up your Mac from a hard disk, network volume, or Time Machine backup that contains an incompatible version or build of macOS, you might experience one or more of these symptoms:
Your Mac doesn't finish starting up, or displays a prohibitory symbol at startup.
You see a message that you're using an unsupported or incorrect version of the Mac operating system.
Your Mac doesn't respond to your trackpad, mouse, or keyboard.
Apps unexpectedly quit.
Your Mac doesn't sleep or wake.
You don't hear any sound from your Mac.
The fans in your Mac are louder, because they're spinning faster.
The image on your display appears to shrink, has black bars around it, or appears tinted.
You can't use Bluetooth or Wi-Fi.
Which Mac operating systems are compatible?
The version of macOS that came with your Mac is the earliest version compatible with that Mac. To find out whether your Mac is compatible with a later version of macOS, check the system requirements:
If your Mac won't start up from a compatible version of macOS, it might require a specific build of that version. To get the correct build, reinstall macOS or upgrade to a later version of macOS.
Learn more
To restore a Time Machine backup that was created on a different Mac, use Migration Assistant.