ip3country
This is 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 speed.
This project in its entirety is <300KB, compared to most alternatives out there that are north of 40MB (but might provide more than just countries).
(Other languages: Python: https://github.com/statsig-io/ip3country-py, Go: https://github.com/statsig-io/ip3country-go, Ruby: https://github.com/statsig-io/ip3country-ruby, Kotlin: https://github.com/statsig-io/ip3country-kotlin, C#/.Net: https://github.com/statsig-io/ip3country-dotnet)
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.
Usage
$ npm install ip3country
// Setup
const ip3country = require("ip3country");
ip3country.init();
// Lookup using ip4 str
ip3country.lookupStr("123.45.67.8"); // 'KR'.
// Lookup using numeric ip
console.log(ip3country.lookupNumeric(2066563848));
Accuracy
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
Binary data
To make this library easy to consume, we're using btoj to transform the necessary binary data into a js module that can be imported like any other module. You won't need to list ip3country as an external in your build process.
We're currently using brotli compression via NodeJS's zlib library, which won't work in Browser environments. If you want ip3country on a browser, check version 3.0.0 (and feel free to publish ip3country-browser).
Name
All variants of "ip2country" were already taken in npm, so we decided to step it up.
Motivation
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.
