Domains & Subdomains Discovery Service | WhoisXML API

Domains & Subdomains Discovery Service allows you to identify all domains and/or subdomains connected by hostname terms

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500 free API requests. No credit card required.

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

Our Domains & Subdomains Discovery Service product line includes:


Just take a hostname search string and instantly get a list of connected domains and subdomains. Get more accurate results according to your needs using advanced search options.

Domains & Subdomains Discovery Lookup | WhoisXML API
Domains & Subdomains Discovery API | WhoisXML API


With one API call, you will get a list of all related domains and subdomains that contain specified hostname strings.

Benefits of Domains & Subdomains Discovery Service

  • Comprehensive and accurate

    Domains & Subdomains Discovery Service supports nearly every top-level domain (TLD), now numbering in excess of 7,298.

  • Up-to-date

    All of the service’s search results are the product of 11+ years’ worth of data crawling and aggregation with daily updates. Our database is expanding at a rate of 1M newly discovered subdomains per day.

  • Well-Parsed

    We normalize and parse our data to give users results in ready-to-use Extensible Markup Language (XML) and JavaScript Object Notation (JSON) files integrable with any business process.

Domains & Subdomains Discovery Service | WhoisXML API

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