What is a WHOIS lookup?

A WHOIS lookup queries a public database for domain registration details including registrar, registration and expiry dates, name servers, and registrant contacts. This tool uses RDAP, the modern structured successor to classic WHOIS.

Why is WHOIS data redacted?

Since GDPR in May 2018, ICANN requires registrars to redact personal data for EU-based registrants. Privacy services, TLD policies, and registrar opt-outs can also cause redaction. The registrant name, email, phone, and address are commonly hidden.

Which DNS records are checked?

The tool checks A (IPv4), AAAA (IPv6), MX (mail exchange), NS (name servers), TXT (SPF, DKIM, DMARC, verification tokens), CNAME (aliases), and SOA (start of authority) records for the queried domain.

What does the DNS health audit check?

The DNS health audit runs 13 checks: SPF record presence and single-record compliance, DMARC record and policy strength, DKIM key detection (common selectors), BIMI, MTA-STS, TLS Reporting, MX redundancy, MX+SPF consistency, CAA records, nameserver redundancy, and SOA serial format. Each check shows pass, warning, or fail with an explanation.

What is Certificate Transparency?

Certificate Transparency is a public append-only log of all SSL/TLS certificates ever issued. This tool shows all certificates issued for a domain, including rogue certificates, with validity periods, issuers, serials, and subdomains discovered via SANs.

Web & Network

Domain WHOIS

Comprehensive domain intelligence: WHOIS registration data via RDAP, DNS records (9 types), DNS health audit (13 checks), SSL certificate transparency, IP geolocation, subdomain discovery, and reputation scanning — all in one dashboard.

Open tool

Quick reference

Category: Web & Network
Runs in: Browser
Data stored: Nothing
Price: Free
Sign-up: Not needed

Browse categories

All features

WHOIS/RDAP registration data with domain lifecycle timeline
DNS records: A, AAAA, MX, NS, TXT, CAA, CNAME, SOA, SRV
DNS health audit: SPF, DKIM, DMARC, MTA-STS, TLS-RPT, BIMI, CAA, NS redundancy (13 checks)
Certificate transparency log search via crt.sh
Subdomain discovery from CT-log SANs + passive DNS
IP geolocation with ISP, ASN, PTR, and mini-map

What you can do

Look up domain registration

Enter any domain to see registrar, creation and expiry dates, EPP status codes, nameservers, and a lifecycle timeline — all via RDAP.

Inspect DNS records

View A, AAAA, MX, NS, TXT, CAA, CNAME, SOA, and SRV records with smart annotations for SPF, DMARC, DKIM, and verification tokens.

Audit DNS health

Run 13 checks covering SPF, DKIM, DMARC, MTA-STS, TLS-RPT, BIMI, CAA, MX redundancy, NS redundancy, and SOA serial format.

Discover subdomains

Automatically extract subdomains from Certificate Transparency SANs and passive DNS, grouped by category (Mail, Dev/Staging, API, Wildcard).

View IP geolocation

See the geographic location, ISP, ASN, PTR record, and timezone of the domain IP address on an interactive OpenStreetMap.

Monitor certificate transparency

View all SSL/TLS certificates ever issued for the domain from crt.sh CT logs — including rogue certificates, with validity periods and SANs.

Private by design

Client-side
No sign-up
Free

Domain WHOIS runs entirely in your browser tab. No data is uploaded, no server processes your input, and no account is required.

Specifications

Data source: RDAP, Cloudflare DoH, crt.sh CT logs, backend proxy
DNS records: A, AAAA, MX, NS, TXT, CAA, CNAME, SOA, SRV (9 types)
DNS health: SPF, DKIM, DMARC, MTA-STS, TLS-RPT, BIMI, CAA, NS, SOA (13 checks)
CT certs: crt.sh log search, validity badges, SANs, issuer
Subdomains: CT-log SAN extraction + HackerTarget passive DNS
Export: JSON, Markdown (full result set)