How to get base domain from the URL in JavaScript

Question

I would like to extract the base domain from the url in javascript. For example for the list of urls listed below I need to get google.com (or google.co.in as the case may be) as the result.

www.google.com
www.google.co.in
www.images.google.com
www.images.google.co.in
google.com
google.co.in
images.google.com
images.google.co.in

Any one got some idea on how to do it. There is no direct method to find the base url in javascript i guess.

Answer 1

You can try this method

var url = 'https://www.petzlover.com/us/search?pet=1&breed=262';

extractHostname(url,true); //petzlover.com

extractHostname(url); //www.petzlover.com

function extractHostname(url,tld) {
      let hostname;

      //find & remove protocol (http, ftp, etc.) and get hostname
      if (url.indexOf("://") > -1) {
          hostname = url.split('/')[2];
      }else {
          hostname = url.split('/')[0];
      }

      //find & remove port number
      hostname = hostname.split(':')[0];

      //find & remove "?"
      hostname = hostname.split('?')[0];

      if(tld){
        let hostnames = hostname.split('.');
        hostname = hostnames[hostnames.length-2] + '.' + hostnames[hostnames.length-1];
      }

      return hostname;
  }

let url = 'https://www.petzlover.com/us/search?pet=1&breed=262';

let longUrl = 'https://www.fr.petzlover.com/us/search?pet=1&breed=262';

let topLevelDomain = extractHostname(url,true); //petzlover.com
let subDomain = extractHostname(url); //www.petzlover.com
let lengthySubDomain = extractHostname(longUrl); //www.fr.petzlover.com

document.getElementById('top-level-domain').innerHTML = topLevelDomain;
document.getElementById('sub-domain').innerHTML = subDomain;
document.getElementById('lengthy-sub-domain').innerHTML = lengthySubDomain;

    function extractHostname(url,tld) {
          let hostname;
    
          //find & remove protocol (http, ftp, etc.) and get hostname
          if (url.indexOf("://") > -1) {
              hostname = url.split('/')[2];
          }else {
              hostname = url.split('/')[0];
          }
    
          //find & remove port number
          hostname = hostname.split(':')[0];

          //find & remove "?"
          hostname = hostname.split('?')[0];
    
          if(tld){
            let hostnames = hostname.split('.');
            hostname = hostnames[hostnames.length-2] + '.' + hostnames[hostnames.length-1];
          }
    
          return hostname;
      }

span{
  font-weight:bold;
  font-size:16px;
}

<div>Top Level Domain: <span id="top-level-domain"></span> </div>
<div>Including sub Domain: <span id="sub-domain"></span> </div>
<div>Including lengthy sub Domain: <span id="lengthy-sub-domain"></span> </div>