Making requests | Documentation | Reverse NS API | WhoisXML API
Products APIs Data Feeds Web Tools Domain Research & Monitoring Enterprise Packages
WHOIS / WHOIS History
WHOIS / WHOIS History

Provide current and historical ownership information on domains / IPs. Identify all connections between domains, registrants, registrars, and DNS servers.

DNS / DNS History
DNS / DNS History

Look into all current and historical DNS / IP connections between domains and A, MX, NS, and other records. Monitor suspicious changes to DNS records.

IP Geolocation / IP Netblocks
IP Geolocation / IP Netblocks

Get detailed context on an IP address, including its user’s geolocation, time zone, connected domains, connection type, IP range, ASN, and other network ownership details.

Domain Research Suite (DRS)
Domain Research Suite (DRS)

Access our web-based solution to dig into and monitor all domain events of interest.

Domain Research Suite (DRS)
Domain Research Suite (DRS)

Get access to a web-based enterprise-grade solution to search and monitor domain registrations and ownership details for branded terms, fuzzy matches, registrants of interest, and more.

Research
Monitoring
White-Label
WhoisXML API Predictive Threat Intelligence
Predictive Threat Intelligence

Detect and block access to and from dangerous domain names before malicious actors can weaponize them. Contact us today for more information.

WhoisXML API Internet Infrastructure
Internet Infrastructure

Unlock integrated intelligence on Internet properties and their ownership, infrastructure, and other attributes.

Enterprise API Packages
Enterprise API Packages

Our complete set of domain, IP, and DNS intelligence available via API calls as an annual subscription with predictable pricing.

Security Intelligence (SI) Suite
Security Intelligence (SI) Suite

Offers complete access to WHOIS, IP, DNS, and subdomain data for product enrichment, threat hunting and more.

Multi-Level API User Administration Now Available - Manage individual API keys for team members in your organization.

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Making requests Output format Error codes Server-to-Server OAuth
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Making requests

API endpoint

GET https://reverse-ns.whoisxmlapi.com/api/v1?apiKey=YOUR_API_KEY&ns=ns2.google.com
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

apiKey

Required. Get your personal API key on the My products page.
ns

Required. Name server.
from

Optional. The domain name which is used as an offset for the results returned.

Since every response is limited to 300 records, you can retrieve the next page by putting the last domain name from the response into this parameter. For example, if the last domain name in the response is test.com and the field "size" in the output equals 300, in order to retrieve the next page, call

https://reverse-ns.whoisxmlapi.com/api/v1?apiKey=YOUR_API_KEY&ns=ns2.google.com&from=test.com

If the parameter is omitted, you get arbitrary 300 records.

To get the first page, put 1 into the parameter.
includeAdditionalChecks

Optional. By default, no additional checks are performed.

0 – The response is returned as normal. 1 request costs 5 DRS credits.

1 – In this mode, the API performs two additional DNS checks: wildcard check and domain activeness check. Such a query takes a bit longer to execute and 1 request costs 7 DRS credits.

wildcard check – The API checks if the DNS record is part of a wildcard entry.

domain activeness check – The API checks if the domain's DNS records can be retrieved.

Acceptable values: 0 | 1

Default: 0
outputFormat

Optional. Response output format.

Acceptable values: JSON | XML

Default: JSON

Free access

After Sign Up you automatically get a free subscription plan limited to 500 DRS credits.

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.