Check domain availability with Javascript

Javascript domain check with API

I see that a lot of people use Google for “javascript domain check,” so I thought I would help them with the subject. Especially since WhoAPI’s currently most popular function is domain availability checking. But only a small percentage of people that, include experts and developers, know the difference between 1 domain availability check (with a captcha haunting you) and 100 000 daily domain availability checks with our API. With a domain availability API, you can build the domain checker, that’s the biggest difference.

Here’s a great example of how you can build a service for domain availability checks (without a captcha). The thing is if you want to use Javascript and check domain availability, you only need to connect to an API. Let someone else do the hard lifting for you. You do something that you are passionate about! If you tried our Webmaster.Ninja domain checker (discontinued in August 2022), you probably saw that it was powered by our domain availability API, which does the heavy lifting. But honestly, there are so many bulk domain checkers you could build anything.

Javascript code example for domain availability checks

[source language=”javascript”]

var domain = “”; // domain name you want to check
var rtype = “status”; // check availability
var apikey = “b7ca3c60b14c2333cdd70fbd6b7bab1f”; // your API key// make API call
if(data.indexOf(“error:”) == 0){
// translate error
$.get(‘’+data, function(data) {
$(‘#result’).html(‘Error: ‘+data);
// show the result
$(‘#result’).html(‘Domain availability: ‘+data);

[please wait]

So basically, you are checking if the domain name “” is available. If an error occurs, it will be translated automatically, if not, you should see “1” (signals the domain name is taken) as a result string. It’s practically the same with PHP.

Unfortunately, you will have to pay a fee for using this solution, so be creative. Meaning, find a way to offer this service so it’s profitable for you too. Naturally, you cannot charge for someone to check domain availability on your website, but I am sure you already found a way you can profit from this (since you are reading this). And if you haven’t, then continue following this blog! I am sure we will write now and then about the huge potential that can come out of this.

WhoNS - Check domain availability with Javascript.

WhoNS – Our discontinued service that we built in order to check domain availability with Javascript.

Are you building a domain checker with JavaScript?

For example, why not build a script, or go that far to building a bulk domain checker to help new companies find available domain names? But in a way, they insert 20-200 keywords in one box and 20-200 (or just pick a number) in another box (your script cross-lines the keywords) and deliver the available domain names. That would be cool. The thing is, if you make 200×200 checks, you would need 40 000 checks. Can you imagine a person going hand-by-hand inserting 40 000 names and each time inserting a captcha? It would drive them nuts! Write to us what you think about this idea, or just comment below!

If, however, you want a free way to do javascript checking of domain availability, you are probably going to have a hard time finding an adequate solution. The reason this is true is that you need to have the infrastructure and the technology to perform massive lookups. Regardless, be it JavaScript, Ruby, or Python. Big domain registrars aren’t interested in giving up their infrastructure, and it’s beginning to be a never-ending problem. So, you got to make sure you can afford the querying – find the right niche and offer value-added service, and solve a problem for your clients. Which then, in return, they will be happy to pay for.
As the number of TLDs and domain names keeps growing, I think more and more companies, developers, and solopreneurs will “succumb” to checking domain availability with Javascript and other automated ways.

Example domain checker built with an API

Take one of our Webmaster Ninja tools (discontinued in August 2022), for example. It didn’t take us a lot to build a powerful and unique domain checker with just a smidge of JavaScript and API. Now with just a dozen keywords with the power of compounding, you can do thousands of domain checks and potentially find hundreds of available domains. Also, it’s different from every other “domain mashup” tool because the majority of the creative process and power remain in the user’s hands. What do I mean by that?

You pick the keywords and “domain parts”

In every other domain mashup tool and domain suggestion tool I’ve seen in the past 10 years, the creative process and user’s power are limited to a single keyword. No wonder the suggestion after that is just no good! is taken, would you like

Take the example above. How in the world is that relevant? Sure, the keyword domains in the TLD are there, but the domain “realms” could have been any word.,,, Not relevant, not usable.

But what if I chose a particular set of keywords and was interested to see if there are any combinations that are available for registration, wouldn’t that be more relevant? If, for some reason I particularly liked the keywords: go, good, goal, and domain, domains, names, a name, I could easily check 24 different combinations with 100% relevancy because I picked the keywords.

Domain Checker

Example of domain checker on (discontinued in August 2022)

Have you ever built your own domain checker?

Looking for great domain names available for registration can be a boring, difficult, and time-consuming job. It can also get depressing since most of the time, you are getting the “taken” result.  Here are some examples of why someone might be looking for a new and fresh great domain.

  • New business or venture seeking available domains
  • An existing business trying additional domains for their new product or service launch
  • Personal website or side project
  • Finding domain names for AdWords campaign or SEO campaign

So it’s not surprising that developers build their own unique domain checker to help them find great domain names.

Domain availability API can help you build a domain checker

Domain Availability API can help you build a domain checker

How will your domain checker built with JavaScript help you?

The point is that over 100 million .com domains are taken, and there are over 220 million domains across all TLDs. What does that mean?

Well, for starters, it means most of the words from the English dictionary are taken as domain names. This turns the process of checking domain names one by one very time-consuming, boring, and difficult. You need to brainstorm a lot, and you may make an even bigger mistake of building your project on a domain like

Buying an old premium LLLL domain like (which has been around since 1996) is expensive. As we know, LLLL domains are no longer available for new registration and are only available on the aftermarket. If you are looking for a cost-effective solution, then the best way is to make a bulk query! Just write 50 keywords, make all sorts of combos, and query WhoAPI. In an instant, you will receive available names and choose one or two that you find most attractive.


Also, if you are looking for some keyword-heavy domains, even better! Just export keywords from your favorite keyword generator tool (hint, hint) and make 10000 queries, and snap the domains everybody else missed! So why not give our domain availability API a try?


Goran Duskic has been the Founder and CEO of WhoAPI Inc. since 2011, a company that specializes in developing APIs, including the well-known Whois API. He started his career in internet entrepreneurship in 2006 and has co-founded several online businesses, including a web hosting company that he later sold. Goran's work primarily involves creating practical API solutions to meet technological needs.


  1. Phaphama Jabavu says:

    Hi What would the HTML code look like for the above, I suspect it would be a form that calls the javascipt, am I correct?

    1. Goran Duskic says:

      Yes. It largely depends on the design you want to have around the “checker” itself. It also depends if you used javascript or other scripting languages in order to create the “checker”.

      For example, here you can see other code examples for scripting languages such as PHP, Ruby, Python, Objective C, .Net and Javascript.

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