A library for parsing IPv4 and IPv6 IP addresses in node and the browser.

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8.1.0a year ago7 years agoMinified + gzip package size for ip-address in KB


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ip-address is a library for validating and manipulating IPv4 and IPv6 addresses in JavaScript.

Migrating from 6.x to 7.x

ip-address was rewritten in TypeScript for version 7. If you were using version 6 you'll need to make these changes to upgrade:
  • Instead of checking isValid(), which has been removed, you'll need to use a
try/catch if you're accepting unknown input. This made the TypeScript types substantially easier as well as allowed the use of an AddressError class which will contain a parseMessage if an error occurred in the parsing step.
  • Instead of using the error, parseError, and valid attributes you'll
need to use the message and parseMessage of the thrown AddressError.


Documentation is available at ip-address.js.org.


var Address6 = require('ip-address').Address6;

var address = new Address6('2001:0:ce49:7601:e866:efff:62c3:fffe');

var teredo = address.inspectTeredo();

teredo.client4;    // ''


  • Usable via CommonJS or ESM
  • Parsing of all IPv6 notations
  • Parsing of IPv6 addresses and ports from URLs with Address6.fromURL(url)
  • Validity checking
  • Decoding of the Teredo
information in an address
  • Whether one address is a valid subnet of another
  • What special properties a given address has (multicast prefix, unique
local address prefix, etc.)
  • Number of subnets of a certain size in a given address
  • Display methods
- Hex, binary, and decimal - Canonical form - Correct form - IPv4-compatible (i.e. ::ffff:
  • Works in node and the browser (with browserify)
  • ~1,600 test cases

Used by

@congressedits, among many others Contrail, a network virtualization solution made by Juniper Networks software quickly geolocating IP addresses automation bus hosted on Heroku implementation based on IPFS server written in JavaScript reading MaxMind database files protocol encoder/decoder built by Ably database API University of Portsmouth extension for switching between multiple proxies with ~311k users!
  • swiz: a serialization framework built
and used by Rackspace