You can check the system requirements for FileMaker Pro and Server on the Claris website.
In general there are two sides: First you install FileMaker software on a supported OS to receive support in case something doesn't work. On the other side, you may still use an older computer with an older operation system. Eventually you may need to upgrade the computers and OS as you want to get security fixes and not loose your valuable data to some malware attack.
FileMaker Pro
FileMaker Pro operating system requirements
FileMaker Pro for macOS is listed to work on macOS 14 and macOS 15. But FileMaker 2024 and 2025 launches and operates fine on macOS 13.7. So if you still use an older Mac, you can still enjoy FileMaker Pro on your own risk.
We expect that Claris will make an update for macOS 26 in the fall. Then they may change the system requirements, both listed on their website and technically.
For Windows, the recommended version is 10 and 11 in Pro or Enterprise editions. But of course it runs on Home edition, too. It does however not run on Windows 8 anymore due to FileMaker using newer libraries, that didn't exist back on Windows 8.
FileMaker Server
FileMaker Server operating system requirements - all versions
We recommend to use Linux for Servers as about 70% of the servers used by our clients already use Linux. Unless you need a specific feature on macOS or Windows, you go with the Linux server. Yes, sometimes you use an existing Windows server or maybe an existing Mac in a small business. But the default should be FileMaker Server running on a hosted server.
Fox Linux, please keep it simple and install the exact Linux version listed by Claris. They link to libraries, that may not exist on different versions or different distributions.
For Windows, Claris supports Windows Server 2019 and 2022. That is what they support officially. But technically the server can of course run on other Windows variants. For years I run FileMaker Server on Windows 10 in a VM. Great for testing plugin functions locally.
While not listed on the system requirements page, FileMaker Server seems to run fine on Windows Server 2025. We tried it and it seems to work just fine, including FileMaker Pro. You may need to do Windows updates first to get up to date with all the libraries.
Eventually Claris will remove the 2019 version and add the 2025 version to their listing. They prefer to only support two versions of Windows Server.
Let us know what your experience is.