You don't say what OS you are using or what software you already have installed.
in my case, under Linux, I use "imhead" on a FITS image file more often than not. This useful little tool is part of the "wcstools" suite which can do far more, including editing a FITS header, (x,y) <-> (ra,dec) conversion, rotating and/or reflecting images, and more.
I don't do Windows myself but I see no reason why wcstools shouldn't work there, especially under WSL. The main site is
http://tdc-www.harvard.edu/wcstools/ where it is claimed "
This software is all written in very portable C, so it should compile
and run on any computer with a C compiler." Someone,. somewhere must have built a Windows version at some time in the last twenty years!
In my experience, MacOS is sufficiently Unix-like that compiling from source is generally straightforward.
Paul