What OS X can I upgrade to on an iMac mid-2011?
What OS X can I upgrade to on an iMac mid-2011, 21.5inch (I have upgraded memory to 32GB)..?
I have upgraded to Sierra (10.12) so far.
iMac 21.5″, macOS 10.12
Welcome to the Apple Support Communities.
You can upgrade to macOS High Sierra. First, backup your Mac. Next, download macOS High Sierra using Safari here: How to get old versions of macOS - Apple Support. Finally, follow the prompts to run the installer and upgrade.
Jack
