ICANN WHOIS Sunset 2025: What Changed for gTLDs

Timeline and impact of ICANN's gTLD WHOIS sunset—operator obligations, developer migration, and security workflows.

Policy context

ICANN registry agreement amendments removed the contractual requirement for port-43 WHOIS on gTLDs. RDAP is now the authoritative access protocol.

Developer impact

  • Scripts hard-coded to WHOIS hosts may fail without warning.
  • Implement IANA bootstrap and referral chains for thin registries.
  • Track per-TLD RDAP availability and redaction notices.

Security & brand teams

Public RDAP may redact registrant fields. Lawful unredacted access uses RDRS or registrar channels—not bulk scraping.

Migration checklist

  • Swap WHOIS libraries for RDAP
  • Map JSON instead of regex
  • Add retry/cache for 429/5xx
  • Monitor TLD coverage