best os for a 2017 imac that won't slow down performance. I've upgraded to a solid state drive + added RAM. Currently installed Sierra 10.12.6. But many browsers and applications (like Zoom) don't support this version.
[Re-Titled By Moderator]
iMac 21.5″, macOS 10.12
How to download and install macOS - Apple Support
It would be a good idea to make a bootable clone backup of your system before upgrading … just in case you run into any problems.
Note that Catalina and later break 32-bit applications, and replace iTunes with separate applications.
If you have an iTunes Library, be sure to hold onto a copy of your old one until you can verify that everything got over into your Music and TV libraries. I'm not sure how well conversion will work if you go directly from Sierra to Ventura (an upgrade of six major versions).
You can upgrade up to the latest version of macOS 13 Ventura.
What latest macOS is my iMac 2017 compatible to?
