How to extract the hostname portion of a URL in JavaScript

Let's suppose you have this url path:

http://localhost:4200/landing?query=1#2

So, you can serve yourself by the location values, as follow:

window.location.hash: "#2"
​
window.location.host: "localhost:4200"
​
window.location.hostname: "localhost"
​
window.location.href: "http://localhost:4200/landing?query=1#2"
​
window.location.origin: "http://localhost:4200"
​
window.location.pathname: "/landing"
​
window.location.port: "4200"
​
window.location.protocol: "http:"

window.location.search: "?query=1"

Now we can conclude you're looking for:

window.location.hostname

There is another hack I use and never saw in any StackOverflow response : using "src" attribute of an image will yield the complete base path of your site. For instance :

var dummy = new Image;
dummy.src = '$';                  // using '' will fail on some browsers
var root = dummy.src.slice(0,-1); // remove trailing '$'

On an URL like http://domain.com/somesite/index.html, root will be set to http://domain.com/somesite/. This also works for localhost or any valid base URL.

Note that this will cause a failed HTTP request on the $ dummy image. You can use an existing image instead to avoid this, with only slight code changes.

Another variant uses a dummy link, with no side effect on HTTP requests :

var dummy = document.createElement ('a');
dummy.href = '';
var root = dummy.href;

I did not test it on every browser, though.

Regex provides much more flexibility.

    //document.location.href = "http://aaa.bbb.ccc.com/asdf/asdf/sadf.aspx?blah
    //1.
     var r = new RegExp(/http:\/\/[^/]+/);
     var match = r.exec(document.location.href) //gives http://aaa.bbb.ccc.com

    //2. 
     var r = new RegExp(/http:\/\/[^/]+\/[^/]+/);
     var match = r.exec(document.location.href) //gives http://aaa.bbb.ccc.com/asdf

My solution works in all web browsers including Microsoft Internet Explorer and doesn't use any regular expression, it's inspired of Noah Cardoza and Martin Konecny solutions:

function getHostname(href) {
    if (typeof URL === 'object') {
        // workaround for MS IE 11 (Noah Cardoza's solution but without using Object.assign())
        var dummyNode = document.createElement('a');
        dummyNode.href = href;
        return dummyNode.hostname;
    } else {
        // Martin Konecny's solution
        return new URL(href).hostname;
    }
}

You can split the URL string using /

const exampleURL = "Https://exampleurl.com/page1/etc/etc"
const URLsplit = exampleURL.split("/")
console.log(URLsplit)
console.log(URLsplit[2])

Result. exampleurl.com