Imac 2.9Ghz Intel Core i5 8Gb os x Yosemite

According to MacTracker,

• You can upgrade a Mid 2015 iMac to Big Sur – and no further
• You can upgrade any of the Late 2015 iMacs to Monterey – and no further

MacTracker is not showing that any of these iMacs ever shipped with a 2.9 GHz Intel Core i5. Please double-check which iMac you have (model and hardware release year) using About This Mac in the Apple () menu.

If you install Catalina or later, 32-bit applications will stop working, and iTunes will go away, replaced by separate applications. Neither Big Sur or Monterey is one of the "most recent three" – but either should be enough to run the current versions of Firefox, LibreOffice, and the commercial Affinity V2 programs (Photo, Designer, Publisher).

Because Yosemite is so old, you might need to do an upgrade in phases:

• Use a modern Mac or PC to download the .DMG containing the Sierra installer and put it onto a USB flash drive. This will NOT create a bootable installer; just a drive with a data file on it.
• Transfer the .DMG to the old Mac, open it, and install Sierra using the installer application inside.
• Once Sierra is running, use its versions of Safari and the App Store to upgrade to, e.g., Big Sur or Monterey.

How to download and install macOS - Apple Support

FWIW, You have either a Late 2012 or Late 2013 iMac. Either can be upgraded to macOS Catalina 10.15.7. As noted, neither will run older 32bit apps or is still supported. It's time to think about replacing a 11-12 year old Mac.

Just wanted to throw in my 2 cents-Yosemite has a big bug… WiFi doesn’t work on it…. I’d suggest El Capitan… your iMac is compatible and El Capitan will run 32 bits… maybe Mojave..??

John B

If one needed to run 32-bit applications, I'd think the best choice would usually be High Sierra or Mojave.

Either is recent enough to run Firefox 115 ESR . This version of Firefox is no longer getting new features, and it was supposed to have stopped getting even "critical security updates." It looks as if Mozilla has decided to offer those for a little bit longer – until March 2025. So it's close to being totally unsupported, but it's probably still leaps and bounds ahead of whatever Web browsers run on Yosemite.

MariaZikou wrote:

Thank you very much for your time and help!

I will buy a new one at last!!!

You're welcome.