Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts, first/last seen and live DNS status.

5 hosts · 251 ms

HostCertsFirst seenLast seenDNS
cybermeister.com 6 2026-05-08 2026-09-03 ok
*.cybermeister.com 6 2026-05-08 2026-09-03 —
yoobi.cybermeister.com 3 2026-03-13 2026-09-21 ok
www.yoobi.cybermeister.com 3 2026-03-13 2026-09-21 nxdomain
mailer.cybermeister.com 5 2026-05-05 2026-10-04 ok

Programmatic access, with DNS A records: API GET /v1/hosts/cybermeister.com (API key for paging).

Shown here: hostnames with a certificate that is valid now or expired within the last 90 days. The full history since 2013 — hostnames whose last certificate expired earlier — is a Pro plan method: GET /v1/hosts-history/cybermeister.com.