Language recognition
Use language as a signal, not as an unwavering assumption.
Belgian visitors can search for Dutch, French or English. Location alone therefore never reliably determines the desired search language.
Chosen language first
An explicit choice of store or user is the strongest signal.
Browser language
Use browser context as a proposal or fallback when no choice is known.
Query language
A search term may have a language other than the interface.
Location
Use land at most as an additional signal, especially in multilingual countries.
Not a hard redirect
Let visitors change when uncertainty exists.
Save preference
Remember a confirmed choice to keep every page and search interaction consistent.