WhoisXML API Reverse WHOIS review
A flexible reverse-WHOIS service for current, historical, and large-scale domain investigations.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
WhoisXML API Reverse WHOIS searches WHOIS records to find domains connected to owner names, organization names, email addresses, phone numbers, or postal addresses. It supports both current and historical records, making it relevant to cybersecurity investigations, brand protection, fraud detection, law enforcement, and market research teams. The service is available through a web interface and a REST API, so it can serve both individual investigations and programmatic workflows.
Search controls are a central strength. Investigators can apply domain creation, update, and expiration date filters, choose exact or fuzzy matching, and combine up to four included terms with up to four excluded terms in a request. Results are returned as structured JSON or XML, and pagination extends beyond 10,000 records. These capabilities give the product a broad scope for tracing domain relationships, comparing historical registration data, and handling larger result sets. The main constraint is that each request has a defined term structure, so complex investigations may need to be divided across multiple searches.
The ecosystem is suited to security and investigation teams that already work with analysis or monitoring platforms. Listed integrations include Splunk, IBM QRadar, ServiceNow, Snowflake, Postman, Maltego, OWASP Amass, Sumo Logic, Pangea, Query.ai, Logpresso, Cyware, ProjectDiscovery, and Malfors. According to the vendor's pricing page, the service uses DRS credits, with one credit consumed per Reverse WHOIS request. Choose it when flexible search logic, historical coverage, API access, and integrations matter; consider an alternative if your primary need is a broader investigation suite rather than WHOIS-focused domain discovery.
WhoisXML API Reverse WHOIS pros and cons
- Where it wins
- Searches names, organizations, emails, phones, and postal addresses
- Combines historical records, date filters, and exact or fuzzy matching
- Supports REST API access, JSON/XML output, and pagination beyond 10,000 records
- Where it doesn't
- Search requests allow up to four included and four excluded terms
- Paid usage follows a DRS-credit model with one credit per request
- Its focus is WHOIS-linked domain discovery rather than broader investigation workflows
WhoisXML API Reverse WHOIS fact sheet, pricing and score →
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