Go to the Apple logo in the top left of your screen and select About This Mac > System Report.Here’s how to check whether the game or app you want to use is 32 or 64-bit compatible. The same applies to some music production or DJ software for Mac that have lots of 32 bit plugins that will no longer work in macOS Big Sur or on an M1 Mac. The most notable program is Microsoft Office 2011 but there are also others like MetaTrader, Adobe CS5 and CS6, Aperture, older versions of iTunes, iBooks, iPhoto and some Steam games which are still 32-bit only. However, the problem for some Mac users is there are still some older applications and games that are still 32-bit only. If you try to run a 32 bit-app in Catalina, Big Sur or an M1 Mac, you’ll get the following “App is not optimized for your Mac and needs to be updated” error message: The latest Apple Silicon M1 chip Macs are also incompatible with 32-bit games or apps and if you’re trying to run 32-bit an M1 Mac, we recommend you skip to the section on 32 bit games and apps on M1 Macs. You can only install 64-bit apps on Big Sur and Catalina which for most people isn’t a problem as almost all major software is now 64-bit.
Apple dropped support for 32-bit applications in macOS Catalina and the last macOS to support them was Mojave. Big Sur and M1 Macs do not run 32-bit apps or games.
