API Documentation

Getting Started


The DomainTools API provides direct access to the same data that drives the powerful research tools on DomainTools.com. It is designed for server-to-server communication between your system and the DomainTools network using standard HTTPS requests. The API can provide responses in both JSON and XML formats and offers a RESTful URL structure for most queries. You can authenticate securely using HMAC authentication (described in detail below) or with simple key/value pairs in the request.

If you wish to use our API products, or require assistance with customized data feeds, contact our Enterprise Solutions team to arrange access:

Professional API Endpoint

The API endpoint for all requests described in this document is:


We also support SSL requests to the Professional API endpoint. We recommend you use the HMAC authentication scheme to protect your API credentials if you are not using SSL.

Response Formats

The API provides responses in JSON format by default. Other formats are available by adding the optional format parameter to your request.

ValueResponse Format
jsonStructured data in Javascript Object Notation


xmlStructured data in XML format


htmlHuman-friendly view useful for debugging and previewing



Free Sample Queries

Most API products provide free, unauthenticated access when you request data on these domain names or IP addresses:

  • DomainTools.com
  • DailyChanges.com
  • ReverseWhois.com

You can use this to evaluate the products in your environment and for low-volume automated testing after you go live. Unless stated otherwise, all example URLs in this document will function normally without authentication. If you provide your authentication credentials for these sample URLs, your account will not be charged (and the authentication will not be validated).

Product Service Levels

A product service level authorizes your API account to access an API product and defines the price and usage limits for that access. If your account is not authorized to access a certain product, contact DomainTools member services for help.

To protect your account from unexpected fees, we apply a usage limit to each product that controls how many requests the API will serve per minute and per month. If the default limits are too restrictive for your needs, contact us and we’ll make adjustments.

General Information