Yes. For decades already. Browsers default it to the OS language, which often indeed is the users preferred language. Relying on GeoIP for language info is don

Yes. For decades already. Browsers default it to the OS language, which often indeed is the users preferred language. Relying on GeoIP for language info is done, I suspect, mostly simply because too many programmers don't know about Accept-Language. So great that you asked. Yes, it works and it's great.