What is whois.b1s4.xyz?

Updated

whois.b1s4.xyz is a web-based DNS and RDAP lookup tool. You open it in a browser, enter a domain name, and it returns DNS records and registration data without requiring an account or any software installation. It is useful when you want to check how a domain is configured, verify mail or name servers, or look up who a domain is registered to.

What it does

The tool covers two related but distinct jobs:

  • DNS record lookup — resolves the records that control how a domain works, including A, AAAA, MX, NS, TXT, CNAME, SOA, CAA and 30+ more record types.
  • RDAP domain lookup — retrieves registration data (the modern, structured successor to classic WHOIS) for a domain.

The site describes itself as "DNS records & RDAP domain lookup," so both functions live in the same interface.

When to use it

Task Relevant lookup
Find the IP address a domain points to A / AAAA
Check where email for a domain is delivered MX
Confirm which name servers are authoritative NS
Read SPF, DKIM or verification strings TXT
See which certificate authorities may issue certs CAA
Check registration details for a domain RDAP

How to use it

  1. Open whois.b1s4.xyz in a browser.
  2. Enter the domain you want to inspect (for example, example.com).
  3. Choose the record type you need, or run the RDAP lookup for registration data.
  4. Read the returned records.

Expected result: a list of records for the type you selected, or registration fields for the RDAP query. No login or install step is involved.

Things to keep in mind

  • DNS answers can be cached, so a recent change may not appear immediately.
  • RDAP registration data is often redacted for privacy, so contact details may be hidden.
  • The tool reports what the queried name servers return; it does not itself host or change your DNS.

If you only need to confirm a single record type, a DNS lookup is enough. If you need ownership or registration context, use the RDAP side.