A zero-dependency, super small, IP address to 2-letter country code lookup library. There are already several libraries available, but none met our requirements for binary size and lookup speed.
This project in its entirety is <700KB, compared to most alternatives out there that are north of 40MB (but might provide more than just countries).
The database used in this project is compacted from IP2Location. Their DB1.LITE edition is provided under CCA, with the attribution below:
NOTE
This site or product includes IP2Location LITE data available from https://lite.ip2location.com.
This library is distributed via jitpack.io.
import ip3country.CountryLookup;
// Lookup using ip4 str
String countryCode = CountryLookup.lookupIPString("123.45.67.8"); // => 'KR'
// Lookup using numeric ip
String countryCode = CountryLookup.LookupIPNumber(2066563848); // => 'KR'
ip3country
's accuracy is dependent on IP2Location LITE's accuracy. In our experience, for country lookups, it is accurate enough for most applications.
IP2Location publishes accuracy reports here: https://www.ip2location.com/data-accuracy
There's also this third party report available: https://www.cl.cam.ac.uk/~nz247/publications/JSAC2011-Geolocation.pdf
All variants of "ip2country" were already taken in npm when we published the original, nodejs verion. Now, we have re-created it for use in kotlin/java clients
At Statsig, we needed a library to evaluate location-based conditions on Feature Gates (Feature Flags). We use ip3country to power country-level rollouts or A/B tests for new features.