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.

13 hosts · 331 ms

HostCertsFirst seenLast seenDNS
trail.cross-join.com 2 2026-05-03 2026-05-03 nxdomain
saam.cross-join.com 8 2026-04-09 2026-09-23 ok
rising-stars.cross-join.com 3 2026-07-27 2026-09-19 ok
*.rising-stars.cross-join.com 3 2026-07-27 2026-09-19 —
chat.cross-join.com 4 2026-04-30 2026-08-17 ok
*.chat.cross-join.com 4 2026-04-30 2026-08-17 —
rising-stars-dev.cross-join.com 3 2026-07-27 2026-09-18 nxdomain
*.rising-stars-dev.cross-join.com 3 2026-07-27 2026-09-18 —
xv-dev.cross-join.com 2 2026-07-27 2026-09-20 nxdomain
*.xv-dev.cross-join.com 2 2026-07-27 2026-09-20 —
xv.cross-join.com 2 2026-07-27 2026-09-20 ok
*.xv.cross-join.com 2 2026-07-27 2026-09-20 —
www.cross-join.com 3 2026-05-18 2026-09-03 ok

Programmatic access, with DNS A records: API GET /v1/hosts/cross-join.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/cross-join.com.