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What Is RDAP, and Why Did It Replace WHOIS?

RDAP is the modern successor to WHOIS — JSON, HTTPS, standardized fields, and access control. Here's the difference and why it matters.

Zro7 WHOIS/RDAP lookups hit the registry directly from your browser — no logging middleman.

RDAP (Registration Data Access Protocol) is the ICANN-mandated replacement for the 1980s WHOIS protocol. It returns the same registration data (registrar, dates, name servers, contacts) as structured JSON over HTTPS, with standardized fields and proper redirects between registries. As of 2025 all gTLD registrars are required to run RDAP; WHOIS remains only for legacy compatibility. Try both side by side with Zro7 WHOIS/RDAP.

WHOIS vs RDAP at a glance

  • Transport: WHOIS = plaintext TCP/43 · RDAP = HTTPS.
  • Format: WHOIS = free-form text (every registry different) · RDAP = JSON with a fixed schema.
  • Internationalization: WHOIS = ASCII-only · RDAP = full Unicode.
  • Access control: WHOIS = anonymous · RDAP = supports authentication (tiered access for law enforcement).
  • Redirects: WHOIS = manual referrals · RDAP = HTTP 302 to the authoritative server.

Why the switch happened

  1. GDPR made publishing personal contact data risky — RDAP allows structured redaction ('privacy' fields).
  2. Parsers kept breaking because every registry formatted WHOIS text differently.
  3. TLS was overdue — WHOIS-over-port-43 is fully plaintext.
  4. IDN domains needed a protocol that supports non-ASCII correctly.

What an RDAP response looks like

  • ldhName: the domain in LDH form (e.g. example.com).
  • status: array of EPP statuses (clientTransferProhibited, etc.).
  • events: registration, last changed, expiration timestamps.
  • entities: registrar and contacts with vCard-format details.
  • nameservers: authoritative NS list.

Is WHOIS dead?

Not yet. Many ccTLDs (country-code TLDs like .de, .uk, .jp) still run WHOIS only. RDAP is mandatory for gTLDs (.com, .net, .org, .app, etc.). Best practice: try RDAP first, fall back to WHOIS.

How to look up a domain

  1. Open Zro7 WHOIS/RDAP.
  2. Type any domain.
  3. Read the standardized JSON view — no format guessing.
  4. Cross-check DNS with DNS Lookup.

Updated December 29, 2026 · Zro7 editorial team.

Frequently asked questions

Is RDAP faster than WHOIS?

Marginally — HTTPS + JSON parsing beats scraping text — but the big win is reliability, not speed.

Can I see the registrant's email?

Rarely — GDPR-driven redaction hides most personal fields. Use the registrar's abuse contact form instead.

Why does RDAP sometimes 302 redirect?

IANA's bootstrap points at the top-level RDAP server, which redirects to the authoritative registry.

Does RDAP show DNSSEC?

Yes — the 'secureDNS' object reports whether DS records are published.

Is RDAP rate-limited?

Yes — most servers cap ~100 queries/minute per IP. Zro7 queries client-side, so limits apply to your IP, not ours.

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