IP lookup using Maxmind databases

Usage no npm install needed!

<script type="module">
  import maxmind from '';



Javascript module for Geo IP lookup using Maxmind binary databases (aka mmdb or geoip2). Fastest Maxmind lookup library available - up to 17,000% faster than other libraries. Module has 100% test coverage with comprehensive test suite. It natively works with binary Maxmind database format and doesn't require any "CSV - {specific lib format}" conversions as some other modules do. Maxmind binary databases are highly optimized for size and performance so there's no point using other formats.

GEO databases

You might want to use geolite2 module with free geo databases. Alternatively, free databases available for download here. If you need better accuracy you should consider buying commercial subscription.


npm i maxmind



const maxmind = require('maxmind');'/path/to/GeoLite2-City.mmdb').then((lookup) => {

});'/path/to/GeoOrg.mmdb').then((lookup) => {



import maxmind, { CityResponse } from 'maxmind';

const lookup = await<CityResponse>('/path/to/GeoLite2-City.mmdb');
console.log(lookup.get('')); // inferred type maxmind.CityResponse

console.log(lookup.getWithPrefixLength('')); // tuple with inferred type [maxmind.CityResponse|null, number]

Sync API

You can use Reader class directly, if you would want to instantiate it in non-async fashion. Use cases would include receiving a buffer database over network, or just reading it synchronously from disk.

import { Reader } from 'maxmind';
const buffer = fs.readFileSync('./db.mmdb');
const lookup = new Reader<CityResponse>(buffer);
const city = lookup.get('');

const [city2, prefixLength] = lookup.getWithPrefixLength('');

Supported response types:

- CountryResponse
- CityResponse
- AnonymousIPResponse
- AsnResponse
- ConnectionTypeResponse
- DomainResponse
- IspResponse

V6 Support

Module is fully compatible with IPv6. There are no differences in API between IPv4 and IPv6.

const lookup = await'/path/to/GeoLite2.mmdb');
const location = lookup.get('2001:4860:0:1001::3004:ef68');

Options, [options])

  • filepath: <string> Path to the binary mmdb database file.
  • options: <Object>
    • cache: <Object> Cache options. Under the bonnet module uses tiny-lru cache.
      • max: <number> Max cache items to keep in memory. Default: 6000.
    • watchForUpdates: <boolean> Supports reloading the reader when changes occur to the database that is loaded. Default: false.
    • watchForUpdatesNonPersistent: <boolean> Controlls wether the watcher should be persistent or not. If it is persistent, a node process will be blocked in watching state if the watcher is the only thing still running in the program. Default: false.
    • watchForUpdatesHook: <Function> Hook function that is fired on database update. Default: null.

Does it work in browser?

Current module is designed to work in node.js environment. Check out mmdb-lib that's used under the bonnet - it's environment agnostic and does work in browser.

IP addresses validation

Module supports validation for both IPv4 and IPv6:

maxmind.validate(''); // returns true
maxmind.validate('66.6.44.boom!'); // returns false

maxmind.validate('2001:4860:0:1001::3004:ef68'); // returns true
maxmind.validate('2001:4860:0:1001::3004:boom!'); // returns false

GeoIP Legacy binary format

In case you want to use legacy GeoIP binary databases you should use maxmind@0.6.