Search 184M+ domain records by registrar, nameserver provider, TLD, or date range. Discover portfolios, monitor brands, and research domain infrastructure across 1,200+ TLDs.
Written by Ishan Karunaratne · Last reviewed:
A reverse WHOIS lookup flips the traditional domain lookup on its head. Instead of starting with a domain name and finding its registration details, you start with a characteristic — like a registrar name, nameserver provider, or TLD — and find all domains matching that criteria.
I built this tool to make it easy to explore the domain landscape. Whether you are monitoring your brand across registrars, analyzing a competitor's domain portfolio, or researching which domains are managed by a specific provider, reverse WHOIS gives you the answers without manual lookups.
Find domains registered through your registrar or using your nameservers. Detect unauthorized use of your brand across the domain ecosystem.
Discover domains managed by the same registrar or DNS provider as a competitor. Understand their domain strategy and infrastructure choices.
Search for domains by TLD and date range to find recently registered or soon-to-expire domains in specific extensions.
See how many domains use a specific DNS provider like Cloudflare or AWS Route 53. Useful for market research and provider evaluation.
Most reverse WHOIS tools are either paywalled from the first query, limited to a handful of TLDs, or require you to search by registrant name only — which is largely useless in a post-GDPR world where personal data is redacted from public WHOIS records. DNSChkr's Reverse WHOIS takes a different approach by focusing on the metadata that remains publicly available: registrar, nameserver provider, TLD, and registration dates.
The search runs against a database of 184M+ domain records covering 1,200+ TLDs, refreshed daily. This means results reflect the current state of the domain landscape, not a stale snapshot from weeks ago. The first page of results (50 domains) is always free — no account required, no credit card, no paywall on the initial search.
What makes this particularly powerful is the integration with DNSChkr's full tool suite. A reverse WHOIS search surfaces domains, but then you can drill into any result using the WHOIS Lookup for full registration details and a 7-point security validation, the DNS Inspector for DNS record analysis, or the Website Reputation Checker to flag malicious domains. No other reverse WHOIS tool provides this end-to-end workflow.
DNSChkr offers six WHOIS and domain research tools that work together as a complete domain intelligence workflow — from individual lookups to portfolio-scale analysis:
Together, these tools cover the full domain lifecycle from registration through expiry — with 184M+ records, daily updates, and cross-tool integration that no single WHOIS lookup service provides on its own.