The 4 signals behind a country guess
Region is inferred from the network address, the browser language, the device time zone, and any account or payment details. None of the 4 is authoritative, they disagree regularly, and services differ in which one they trust.
There is no field in a web request that states a country. Every region check is a guess from indirect evidence, which is why travellers and people on unusual networks meet strange results.
The network address
Addresses are allocated in blocks that are mapped to countries in databases. The mapping is roughly right and regularly stale, especially for mobile networks and large providers. This is the signal most services use and the one most often wrong at borders.
The browser language
Your browser sends a language preference. It correlates with country and is not the same thing: a person who prefers English in Germany sends English. Services using this alone produce the most visibly wrong guesses.
The device time zone
A rough continental signal, easy to read and easy to change. It is usually a tiebreaker rather than a primary source, because it is coarse and because people travel with laptops that never update it.
Account and payment details
The strongest signal, and only for services that have an account. A billing country is stated by you and verified by a payment network, which makes it far more reliable than any inference. A service with no account has none of this, so it works from the first 3 or from nothing.
Straight answers
Why do 2 services disagree about where I am?
Because they weight the 4 signals differently and use different address databases. Disagreement is the normal state rather than a sign of a fault.
Does the browser send my location?
Only with permission, and precise location is a separate request you would have seen. Region checks do not use it.
Can a wrong guess be corrected?
Where a service exposes a country setting, yes. Where it does not, the guess is the answer and nothing on your side changes it.
See what a service that reads none of the 4 does instead.
Open unblocked chat