iMac 27inch late 2012, runs macOS Catalina 10.15.7

A late 2012 27" iMac can run 10.15.7, you can get it by clicking https://support.apple.com/en-us/106405. That is the very last version a 2012 27" iMac can run. If you need later versions of Mac OS, it is time to pull the trigger on the new Mac you have been wanting.

Good luck!

You can't upgrade higher than macOS Catalina. If you want a later macOS you need to upgrade your Mac for a newer model.

One thing to consider doing is to recycle the 27" and purchase a new Mac mini and a 27 Display. This outlay will cost anywhere between $1200-1500 depending on the display you select. The Mac mini will FAR outperform your 27" in every respect. Migrating your data from your Time Machine backup of the 27" is dead easy to do.

Apple offers free recycling and can finance your new machine with no interest.

navdeep191 wrote:

Thank you. What happens to this Mac then? A lot of Apps don't work with this Mac but the computer works very well otherwise.

If you already have the applications you need, you could just keep using the Mac a while longer. Catalina – and its version of Safari – aren't getting any security updates, but if you're careful about where you go on the Internet and are aware of how not to fall for common "phishing" and "tech support" scams, you can keep using an old machine for a while. Installing a third-party Web browser like Firefox (see below) might help with sites that complain about older versions of Safari.

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As far as getting more applications …

Microsoft and Adobe don't support anything other than "the most recent three" (currently Monterey, Ventura, and Sonoma). Apple ties Safari updates to macOS updates.

There are alternatives.

• The current version of Firefox runs on Catalina, and you could install it as a second Web browser.
• The current version of LibreOffice runs on Catalina, and can work with many Microsoft Office documents.
• The commercial Affinity V2 applications (Photo, Designer, Publisher) run on Catalina. Affinity Photo V2 is a full-featured photo editor that might provide one alternative to Photoshop and Photoshop Elements.
• There are also other Open Source and/or Free Software tools (GIMP, RawTherapee, darktable) that will probably run on Catalina, if you're looking for something a little different than what Photos will do for you.