PSL (Public Suffix List)

JavaScript module for parsing hostname, based on the The Public Suffix List.

The Public Suffix List

A "public suffix" is one under which Internet users can (or historically could) directly register names. Some examples of public suffixes are .com, .co.uk and pvt.k12.ma.us. The Public Suffix List is a list of all known public suffixes.

See https://publicsuffix.org/ and the Wiki link above for more information.

How to Use

Include psl.js as a module and import to use.

parse() returns an Object with the following properties:

• subdomain: string parts before the domain
• domain: string domain name (i.e. sld + tld)
• sld: string Second level domain (i.e. domain without tld)
• tld: string Top level domain (i.e. The Public Suffix)

Example

import {PSL} from './psl.js';


// hostname without subdomain
const psl1 = PSL.parse('example.com');
console.log(psl1.subdomain);    // ''
console.log(psl1.domain);       // 'example.com'
console.log(psl1.sld);          // 'example'
console.log(psl1.tld);          // 'com'

// hostname with subdomain
const psl2 = PSL.parse('www.example.com');
console.log(psl2.subdomain);    // 'www'
console.log(psl2.domain);       // 'example.com'
console.log(psl2.sld);          // 'example'
console.log(psl2.tld);          // 'com'

// hostname with nested subdomains
const psl3 = PSL.parse('a.b.c.example.com');
console.log(psl3.subdomain);    // 'a.b.c'
console.log(psl3.domain);       // 'example.com'
console.log(psl3.sld);          // 'example'
console.log(psl3.tld);          // 'com'