WHOISDR TOOLKIT

Domain intelligence.
One powerful toolbox.

Research domains, DNS, IP addresses, email authentication, TLS certificates, redirects and web infrastructure from one clean interface. Historical intelligence is available with WHOISDR Pro.

Run Domain AnalyzerCompare Free & Pro

Domain Intelligence

Purpose-built utilities for faster investigation and troubleshooting.

Domain Analyzer

Run an all-in-one domain investigation with DNS, registration, SSL, HTTP and infrastructure signals.

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RDAP Lookup

Query modern RDAP registration data for a domain and inspect registrar, dates, status and entities.

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Domain Age Checker

Estimate a domain’s age from available registration creation dates.

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Certificate Transparency Search

Discover certificate names and possible subdomains observed in public Certificate Transparency logs.

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Website Archive History

Find historical website snapshots indexed by the Internet Archive and open archived captures.

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DNS

Purpose-built utilities for faster investigation and troubleshooting.

DNS Record Explorer

Inspect A, AAAA, MX, NS, TXT, CNAME, SOA, CAA and other public DNS records.

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A Record Lookup

Find IPv4 addresses published in A records for a hostname.

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AAAA Record Lookup

Find IPv6 addresses published in AAAA records for a hostname.

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MX Lookup

Find mail exchangers and priority values for a domain.

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Nameserver Lookup

Find authoritative nameservers published for a domain.

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TXT Record Lookup

Inspect TXT records used for verification, email policies and other published data.

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CNAME Lookup

Find canonical-name aliases for a hostname.

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SOA Lookup

Inspect Start of Authority data for a DNS zone.

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CAA Record Lookup

Inspect Certificate Authority Authorization records published for a domain.

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DNSSEC Checker

Check for DS and DNSKEY records that participate in DNSSEC validation.

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DNS Propagation Checker

Compare DNS answers from multiple public resolvers to spot propagation differences.

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Email Security

Purpose-built utilities for faster investigation and troubleshooting.

SPF Checker

Find and inspect SPF policies published in DNS TXT records.

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DMARC Checker

Find and inspect the DMARC policy published for a domain.

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DKIM Checker

Check a DKIM selector and inspect its published public-key record.

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BIMI Checker

Check the default BIMI DNS record used to advertise a brand logo and related verification information.

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MTA-STS Checker

Check the MTA-STS DNS record and fetch the published HTTPS mail transport security policy.

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TLS-RPT Checker

Check the SMTP TLS Reporting DNS policy published at _smtp._tls for a domain.

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DNSBL / RBL Checker

Check a public IPv4 address against several well-known DNS-based blocklists and show each result separately.

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Network

Purpose-built utilities for faster investigation and troubleshooting.

IP Lookup

Inspect public IP metadata, ASN, network ownership, geolocation and reverse DNS where available.

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Reverse DNS Lookup

Resolve an IP address to its PTR/reverse-DNS hostname.

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ASN Lookup

Look up an ASN from a public IP address or inspect public routing metadata for an ASN.

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ASN Prefix Explorer

Explore IPv4 and IPv6 prefixes publicly announced by an autonomous system using public BGP routing data.

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CIDR / Subnet Calculator

Calculate IPv4 network, broadcast, netmask, wildcard mask and usable host ranges from CIDR notation.

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Web

Purpose-built utilities for faster investigation and troubleshooting.

SSL Certificate Checker

Inspect a site’s TLS certificate, issuer, validity period, subject names and expiration.

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HTTP Headers Checker

Inspect HTTP response headers, status code, server hints and security headers.

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Redirect Checker

Trace HTTP redirects and inspect each hop from the starting URL to the final destination.

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Security Headers Checker

Inspect common browser security headers including HSTS, CSP, X-Frame-Options and Referrer-Policy.

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Technology Checker

Detect basic public technology hints from response headers and HTML signatures.

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Robots.txt Checker

Fetch a site’s robots.txt and review crawler directives.

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Sitemap Checker

Check whether a conventional XML sitemap is reachable and inspect its response.

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Website Status Checker

Check HTTP availability, response code, final URL and approximate response time.

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SSL Expiration Checker

Check when a site’s current verified TLS certificate expires and how many days remain.

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Historical Intelligence

Purpose-built utilities for faster investigation and troubleshooting.

PRO

Subdomain Finder

Discover known subdomains using a configured commercial domain-intelligence provider.

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PRO

Reverse IP Lookup

Find domains associated with a public IP using configured provider data.

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PRO

Reverse Nameserver Lookup

Find domains associated with a nameserver using configured provider data.

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PRO

SSL Certificate History

Retrieve current and historical certificate observations through SecurityTrails.

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PRO

Historical DNS

View historical A, AAAA, MX, NS, SOA or TXT observations using a configured intelligence provider.

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PRO

Historical Nameservers

See how a domain’s authoritative nameservers changed over time.

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PRO

Historical WHOIS

Retrieve historical registration snapshots from a configured commercial data provider.

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Need historical infrastructure intelligence?

Track previous nameservers, DNS records and registration snapshots through optional commercial data providers.

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