Utilities for IPv4/IPv6 ranges/subnets/masks parsing/matching, string representations, ...

Usage no npm install needed!

<script type="module">
  import ipMatching from 'https://cdn.skypack.dev/ip-matching';



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Standalone module with some handy features regarding IPs:

  • Quick and easy-to-use way to check whether an IP meets a requirement
  • Support for IPv4/IPv6 wildcard addresses, ranges, subnetworks and masks.
  • Supports both parsing and outputting all common IPv6 notations
  • Utility methods, e.g. next/previous IP, range to a list of CIDRs, ...
  • Every release is thoroughly tested and linted before published


npm install --save ip-matching
# or
yarn add ip-matching

Comes with its own built-in TypeScript declarations with included documentation.


import { getMatch, IPMatch, IPSubnetwork, IPRange, matches } from 'ip-matching';

// matches(ip: string | IP, target: string | IPMatch): boolean;

matches('', ''); // true
matches('', ''); // false
matches('abc::def', 'abc:*::def'); // true
matches('abc::def', 'abc:9::def'); // false
matches('0001:2:3:4:5:6:7', '1:2:3:4:5:6:7'); // true

// getMatch returns an instance of
// IPv4, IPv6, IPRange, IPSubnetwork or IPMask, all extending IPMatch
const mySubnet: IPMatch = getMatch('fefe::0001:abcd/112');
mySubnet.type; // 'IPSubnetwork'
mySubnet instanceof IPSubnetwork; // true
mySubnet instanceof IPMatch; // true
mySubnet.toString(); // 'fefe::1:0/112'
mySubnet.matches('FEFE::1:bbbb'); // true
mySubnet.matches('FEFE::2:bbbb'); // false
mySubnet.equals(new IPSubnetwork(new IPv6('fefe::1:abcd'), 112)); // true
mySubnet.getAmount(); // 65536
(mySubnet as IPSubnetwork).getLast().toString(); // 'fefe::1:ffff'

const myIp = new IPv6('a:0:0::B:0:C');
myIp.toString(); // 'a::b:0:c'
myIp.toLongString(); // 'a:0:0:0:0:b:0:c'
myIp.toFullString(); // '000a:0000:0000:0000:0000:000b:0000:000c'
new IPv6('::ffff:a9db:*').toMixedString(); // '::ffff:169.219.*.*'

const myRange = getMatch('') as IPRange;
myRange.convertToMasks().map((mask: IPMask) => mask.convertToSubnet().toString());
// [ '', '', '' ]

const mask1 = getMatch('') as IPMask;
const mask2 = getMatch('') as IPMask;
mask1.isSubsetOf(mask2); // true
mask2.getAmount(); // 2147483648

getMatch('a::abbc:1234/ffff::ff80:000f').toString(); // 'a::ab80:4/ffff::ff80:f'

Note: The matches function and all constructors error for invalid inputs

You can take a look at the test code or the TypeScript declarations for all the features.

Allowed patterns

  • IP (IPv4/IPv6)
    • Regular IPv4:
    • Wildcard IPv4: 10.0.0.* or even 10.*.0.*
    • Regular IPv6: 2001:0db8:85a3:0000:0000:8a2e:0370:7334
    • Shortened IPv6: 2001:db8:85a3::8a2e:0370:7334 or :: or ::1 or a::
    • Wildcard IPv6: 2001::* or even 2001::*:abc:*
    • Mixed IPv6 (mapped IPv4): ::ffff: (no wildcards allowed in IPv4 part)
    • Not allowed: 10.0.1*.0 or 2001::a*c
  • IP Range
    • IPv4:
    • IPv6: 2001::abc-2001::1:ffff
    • Note: Left side has to be "lower" than the right side
  • IP Subnetwork
    • IPv4:
    • IPv6: 2001::/123
  • IP Mask
    • IPv4:
    • IPv6: 2001:abcd::/ffff:ff8::

The IPMask's toString() method does not automatically simplify e.g. / to /8, even though those are equivalent. Since 2.0.0, IPMask comes with a method convertToSubnet() which returns an equivalent IPSubnetwork if possible, otherwise undefined.