Cloudflare IP

A small utility to test if an IP address belongs to Cloudflare. This is based off their publicly available list of IP Ranges. This utility automatically re-fetches that list once every 24 hours, and it has historically only changed once every few years, so your library should always be up to date.

Installation

To install, run the following command in your terminal:

yarn add @authentication/cloudflare-ip

Usage

Calling isCloudflareIp returns true if the IP address is within the range used by Cloudflare and false if it is not within the range used by Cloudflare.

import isCloudflareIp from '@authentication/cloudflare-ip';

// non-cloudflare ips should be false
isCloudflareIp('66.249.66.1')           // false
isCloudflareIp('1.1.1.1')               // false

// localhost should be false
isCloudflareIp('127.0.0.1')             // false
isCloudflareIp('::1')                   // false

// cloudflare ips should pass
isCloudflareIp('103.21.244.0')          // true
isCloudflareIp('2400:cb00:0000::0000')  // true

const isCloudflareIp = require('@authentication/cloudflare-ip');

// non-cloudflare ips should be false
isCloudflareIp('66.249.66.1')           // false
isCloudflareIp('1.1.1.1')               // false

// localhost should be false
isCloudflareIp('127.0.0.1')             // false
isCloudflareIp('::1')                   // false

// cloudflare ips should pass
isCloudflareIp('103.21.244.0')          // true
isCloudflareIp('2400:cb00:0000::0000')  // true

If you pass in a string that does not represent a valid IPv4 or IPv6 address, an error will be thrown.