Bulk WHOIS API | Easy Access to Bulk WHOIS Data | WhoisXML API

Bulk WHOIS API gives you parsed domain WHOIS ownership information for a list of domains and IP addresses

Do you want to know who is behind the domains and connected IP addresses in your database? Bulk WHOIS API can retrieve all corresponding WHOIS records with a single query. Upload your existing data and download the result in CSV format.

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500 free API requests monthly. No credit card required.

721M+Domains tracked
52K+Satisfied customers
13.7 Billion+WHOIS records

We provide flexible and reliable bulk API processing

  • Completeness

    All data points contained in WHOIS records are made available through Bulk WHOIS API. This includes registrants’ contact information and address, registrar, and domain dates (creation/domain age, expiration, updates, etc.).

  • Consistency

    Our bulk API gives out WHOIS information in a consistent format. That way, you can readily use the results because they are compatible with your systems.

  • Flexibility

    Our API gives you the flexibility to upload multiple domain lists and download separate results with unique request IDs for each file.

  • Convenience

    You don’t have to worry about compatibility. Our API returns results containing parsed and raw data in either Extensible Markup Language (XML) or JavaScript Object Notation (JSON) format.

Practical usage

Cybercrime prevention

Cybercrime prevention

Preventing cybercrime is one of the most challenging enterprises of our time. Staying ahead of perpetrators requires cybersecurity professionals to obtain precise and exhaustive domain data which Bulk WHOIS API can provide.

Law enforcement

Law enforcement officials often need to verify and check domains. The WHOIS database contains vital information for legal efforts as well. Merely possessing the information is not enough, though. Being able to parse key data points with flexibility and for custom solutions is essential.

Domain changes monitoring

Domain names research

Obtaining, selling, and registering domains is easier with WHOIS data. The data itself is not enough, however. That’s why our Bulk WHOIS API is hassle-free, and of course, accurate with all relevant data points.

Marketing research

The sheer amount of information used by global industries is immense. A bulk WHOIS API is essential for companies operating in online arenas and willing to reinforce their existing data and systems. Domain name information can help identify complex trends in the online marketplace and enrich other sources of data.

Brand protection

WHOIS data gathered from Bulk WHOIS API can help you learn more about all the domains that might be using your registered trademarks without your consent.


In search of new business opportunities, partners, or customers? The WHOIS information that we provide may be just what you need. Website owners and managers can rely on WHOIS records to find and contact potential stakeholders using their details.

Payment processing

Payment processors and banks use Bulk WHOIS API to detect transaction fraud as it contains domain ownership information that can help spot discrepancies with the domain records of legitimate entities.

Payment processing

Get 500 free API requests monthly. No credit card required.

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Enterprise API Packages

Get the most out of API access through an annual WhoisXML API subscription. Access pricing is determined based on the number of queries made per month computed at a per-minute rate. Plan your usage according to your available resources.

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Who we are & our Bulk WHOIS Lookup API service

WhoisXML API is a large data and API company that offers services with regard to WHOIS, IP, domain and DNS, as well as threat intelligence data. The organizations served by the company span far and wide; they include government agencies, cyber security firms, brand agents, online payment processors and domain brokers and investors. We provide Bulk WHOIS API records and domain and multiple domain list files uploading service. Since its establishment in 2010, the firm has continually focused on expanding its delivery and reach through strategic alliances and acquisitions. To ensure customer satisfaction, WhoisXML API offers numerous incentives to its wide client base.

The benefits include well-parsed and normalized WHOIS information for easy integration; real time WHOIS data; query results complete with parsed fields and raw texts and key data points for domains. The data points include an email address, registrant name, registration information, organization, domain age and domain availability among other pertinent details. For efficient service delivery, the query results are returned in the popular and user-friendly JSON and XML file formats. The firm’s dedicated WHOIS Web Service hosts WHOIS Record, which covers the registration details of an IP address or domain name. Newly registered clients with free developer account also get to enjoy an unbeatable 500 complimentary API calls.

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WHOIS Lookup API end-user solutions

The information offered by WhoisXML API has numerous practical uses with huge disruptive effects across various industries. Cybersecurity researchers will find the Bulk WHOIS lookup API offered by WhoisXML API absolutely essential for interrogating and curbing cyber crimes as well as creating powerful and up-to-date cyber security and anti-malware solutions. The cyber security solutions can tap into WHOIS API resource-rich database to detect malicious websites, spam, unauthorized intrusions and other online activities that may compromise data integrity. Already, many payment processors and financial institutions are using the WHOIS API to detect fraud and other forms of financial improprieties. Law enforcement agencies together with the local and national security apparatus can also use WHOIS data to accurately identify connected domains, IP addresses, and websites that may be used to permeate crime and fraud.

Businesses led by brand agents can use the data provided on WHOIS platform to safeguard their business interest by checking potential trademark infringements and intellectual property violations all across board. This function is made possible because the WHOIS API’s engine can be deployed at any time to spot domain name duplicates. The WhoisXML API Registrar solution is specifically tailored to pair the backend services offered by the registrar to ensure hassle free domain registration and execution. On matters eCommerce, websites managers and owners can reach out to WHOIS API service to spot business opportunities, partners and potential markets for their products and services. Domain investors are already using the service to identify investment and growth opportunities in untapped markets with an eye on expanding the market and boosting sales.

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Downloading and paying for Bulk WHOIS Lookup API services

Downloading Bulk WHOIS API data with WhoisXML API is easy once you decide the type of data you need and pick the most appropriate format for software tools and download. For data download subscription, users can choose between daily and quarterly data feeds. The quarterly data are organized into lengthy 3-month releases based on database versions while the daily feeds usually reflect the daily changes in domain registrations. For the huge, Bulk WHOIS lookup API datasets, WhoisXML API can help users review the infrastructure setup. However, to perform the review more efficiently and avoid unnecessary delays, significant memory and CPU resources are required.

The data download options available through WhoisXML API range from simple procedure requiring fewer data sets to the more extensive, regular programmed downloading. The most popular downloading options for Bulk WHOIS lookup API data sets are namely; basic download, web access and FTP. Under the basic download procedure, the user pens a directory on a browser and then downloads the selected files. The FTP option is much slower in terms of speed, but offers a comprehensive, full directory listing. With web access, you can use command utilities such as IFTP to write scripts to enable Bulk WHOIS API web access and downloading.

However, the user needs technical knowledge of OS platforms like Mac OSX, Windows, BSD variant scripts and codes like 2 Python. WhoisXML API offers Bulk WHOIS API service at no extra charge to clients with credits. Payments can be made through the query pricing system and membership payment. The Query based payment is highly ideal for corporate clients looking for Bulk WHOIS queries and boundless usage. The query can be bought at any time since it is not time bound. Membership payment package is best suited for businesses that regularly need Bulk WHOIS API. The plan can be changed at any time as needed.

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Get in touch with Bulk WHOIS Lookup API pros

WhoisXML API is trusted by more than 52,000 clients who include “Who is Who” is the tech world. The brands topping the list include Apple, Amazon, EBay Cisco and AT&T. In terms of size, the system operated by the company’s register supports close to 3,000 Top Level Domains (TLDs); this includes Country Code Top-Level Domains (ccTLDs) and Generic Top-Level Domains (gTLDs). Clients can choose the Reverse WHOIS API 2.0 solution to identify domains related to an individual or business and see how they are interconnected. Note that generous restrictions apply to the usage limit and number of domain allowed in each query.

Since its establishment 9 years ago, WhoisXML API has tracked over 300 million domains and searched more than 5 billion records. To facilitate payments, the reputable and trusted online API offers convenient online payment options. More importantly, WhoisXML API offers competitive customer service, which ensures all queries are unhindered and answered in good time. For expedite support, a special email address is provided for reporting support issues, generalized inquiries, and customized WHOIS services or products. A dedicated phone number is also available for non-urgent service catering for enterprise customers.

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