Making requests | Documentation | Domain Availability API | WhoisXML API

Making requests

Domain Availability API helps you check whether a domain name is available for registration quickly and accurately. provides RESTful APIs. It is designed for server-to-server communication between your system and the network using standard HTTP or HTTPS protocols. Query responses are delivered in either XML or JSON format based on your requests which are made via GET method.

To get started you need an account with Authentication is required each time in order to use the API. The first 100 domain name availability lookups are complimentary when you register for a free account.

API endpoint

It takes up to a minute to activate your account after the registration.

Postman collection

Postman is a desktop and web application that allows you to make requests to an API from a graphical user interface. We recommend using Postman with WhoisXML APIs endpoints when exploring the APIs functionality, as well as when you are troubleshooting issues with your application.

The WhoisXML API Postman collection is available at the following links:

The collection includes a preconfigured environment. You will need to set up the api_key variable to fire each request. Get your personal API KEY on the My products page. If you have questions related to the API, contact us.

Input parameters


Required. Get your personal API KEY on the My products page.


Required. The target domain name.


Optional. The default mode is the fastest, the DNS_AND_WHOIS mode is slower but more accurate.

Acceptable values: DNS_AND_WHOIS | DNS_ONLY

Default: DNS_ONLY



DA — Domain Availability API credits will be taken into account when the API is called.

WHOIS — WHOIS API credits will be taken into account when the API is called.

Acceptable values: DA | WHOIS

Default: WHOIS


Optional. Response output format.

Acceptable values: JSON | XML

Default: JSON

Free access

After Sign Up you automatically get a free subscription plan limited to 100 queries.

Usage limits and requests throttling

The maximum number of requests per second is 30. In case that the limit is breached, your subsequent requests will be rejected until the next second.

This API is also available with a dedicated load balancer and premium endpoint to enable faster querying as part of our Premium API Services and Enterprise API Packages.