Domain

These tools let you check both a domain’s registration status and the state of the encrypted connection it serves. You can query the registrant, registration date, and expiry via WHOIS, validate a domain name against the RFCs, and convert between internationalised domain names and Punycode — plus inspect an SSL/TLS certificate’s expiry and issuer and see which TLS protocol versions a server accepts.

Domain WHOIS Lookup (Free)

Free WHOIS/RDAP lookup for any domain. Check the registrar, registrant, registration date, expiry date, and name servers instantly in your browser.

Punycode Converter (Internationalized Domain Names)

Convert internationalized domain names (IDN) containing non-ASCII characters, such as Japanese, to and from Punycode (an ASCII-compatible encoding).

Domain Name Validator (RFC Compliance Check)

Check whether a domain name complies with the RFC 1035/1123 syntax rules. Validates label length, total length, allowed characters, and hyphen placement individually, showing the specific reason for any violation.

SSL Certificate Checker (Expiry & Issuer Lookup)

Enter a domain name to check its SSL/TLS certificate's expiry date, issuer, SAN, and fingerprint. Days remaining are color-coded so you never miss a renewal and risk site downtime.

TLS Protocol Version Diagnostic Tool

Enter a domain name to check which TLS versions (1.0-1.3) it supports. Instantly see whether deprecated legacy versions are still enabled on your server, for free.