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How DomainLookup Works
From the name you type to the record on screen: where the data comes from, how we query it and why some fields can be empty.
1. We Clean the Input
You can paste example.com, https://www.example.com/page or an international domain such as münchen.de. We keep only the hostname, lower-case it, drop a leading www. and convert international characters to Punycode (ASCII).
Anything that is not a valid domain — an IP address, a typo, an email address — is rejected before any request is made. This keeps lookups clean and prevents wasted registry queries.
- URL parsingFull URLs, paths and query strings are stripped down to the hostname.
- Punycode conversionInternational domain names like münchen.de become xn--mnchen-3ya.de for the registry.
- ValidationIP addresses, emails and malformed names are rejected with a clear error.
2. We Find the Right Registry
Every extension — .com, .in, .co.uk — is run by a registry. IANA publishes a public directory that maps each extension to the registry's RDAP service. We use the longest match, so bbc.co.uk goes to the .co.uk service rather than .uk.
For WHOIS we ask whois.iana.org which server handles the extension, then query that server directly. This two-step discovery is why multi-part extensions like .co.in and .com.au work correctly.
- IANA bootstrapThe official directory of RDAP services, updated by IANA.
- Longest-suffix matchEnsures .co.uk wins over .uk, and .co.in over .in.
- WHOIS server discoveryFor .com and .net, the registry only knows the registrar — so we follow the referral for the full record.
3. We Read, Merge and Explain
We query RDAP and WHOIS together. For thin registries like .com and .net, we also follow the registrar's record for fuller details.
Everything is merged into one structured model — registrar, dates, nameservers, status, DNSSEC, contacts and DNS — with plain-language labels.
- RDAPModern JSON replacement for WHOIS — turned into readable tables.
- WHOISOlder plain-text protocol — original text plus parsed fields.
- DNS recordsLive from public DoH resolvers — A, AAAA, MX, NS, TXT, CNAME, SOA, CAA.
- FallbackIf the server is unreachable, your browser queries RDAP directly.
Why a Field Can Be Empty
Domain records are not always complete. Here is why.
Privacy Redaction
Registrant names, emails and phone numbers are usually hidden by the registrar under GDPR and similar laws. We show "Not provided by registry" rather than guess.
Registry Differences
Each registry decides what it publishes. A .in record looks different from a .com record, and some registries publish far less than others.
Rate Limits
Registries limit requests to protect their infrastructure. If you see a rate-limit message, wait a minute and try again.
Data Sources We Use
Everything comes from official, public services — no scraping, no third-party databases.
RDAP
Registration Data Access Protocol — the IANA-managed, structured replacement for WHOIS. Returns JSON over HTTPS.
WHOIS
The legacy port-43 protocol. Still used by many registries and registrars for the registrar-level record.
DNS-over-HTTPS
Public resolvers (Cloudflare 1.1.1.1 and Google 8.8.8.8) provide live DNS records over HTTPS — no backend needed.
What We Do Not Do
No Owner Guessing
If the registry redacts a name, we never try to fill it in from other sources.
No Search History
No accounts, no cookies, no analytics. Each lookup is independent.
No Data Resale
We do not store, sell or share domain records. Results are cached for about 60 seconds only.