Find domains and subdomains related by specific terms in their hostnames

With one API call, you will get a list of all linked domains and subdomains containing specified terms.

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500 free API credits. No credit card required.

2.3 Billion+Subdomains
1 Million+Subdomains discovered daily
52,000+Satisfied customers
14+Years of data crawling


  • Complete and precise

    Our Domains & Subdomains Discovery API works for nearly all top-level domains (TLDs), which now exceeds 7,596.

  • Based on up-to-date data

    All the domains and subdomains that appear in the search results come from a huge database gathered for over 10 years of data crawling. The database is growing daily by an average of 1 million newly discovered subdomains.

  • Unified results

    All information is well-parsed and normalized into either Extensible Markup Language (XML) and JavaScript Object Notation (JSON) format for easy integration with your business processes.

Practical usage

Cybercrime prevention

Cybercrime prevention

Need to know which domains and subdomains may have ties to cybercrime? Domains & Subdomains Discovery API data can help mitigate phishing, malware-enabled, and other attacks.

Cybersecurity solution enhancement

Want to enhance cybersecurity solutions in development? Integrate Domains & Subdomains Discovery API into your solutions and services to better protect your customers against harmful communications and websites, vulnerability exploits, and other threats.

Expand blacklists

Even by merely examining lists of domains and subdomains, you can strengthen protection by including all suspicious entities, even those not identified as indicators of compromise (IoCs), in your blacklists to prevent possible harm.

Marketing research

Need a hand in getting to know your competitors better? Scrutinize their recently-created domains and subdomains to identify potential business expansion avenues. The results can be good jumping-off points for market prospecting and understanding which products are part of an organization’s tech stack, as shown by the presence of certain product names in subdomains.

Marketing research
Brand protection

Brand protection

Want extra protection from trademark and copyright violators? Ensure that lookalike domains cannot adversely affect your brand reputation by fooling your customers and audiences into thinking they are dealing with you. Take action against cybersquatters and fraudsters who aim to benefit from your new product and service launches, settlement initiatives, and other high-profile activities.

Domains & Subdomains Discovery API | WhoisXML API

Get 500 free API credits. No credit card required.

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Premium API Services

Our APIs are available in an enhanced version that offers better performance with a dedicated load balancer and a premium endpoint to enable faster throttling for large-scale API deployments.

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Enterprise API Packages

Annual WhoisXML API access subscriptions are available. Pay based on the number of queries measured monthly at per-minute rates. Our predictable pricing structure allows you to stay on budget.

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