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.

7 hosts · 290 ms

HostCertsFirst seenLast seenDNS
3cx.com 21 2025-09-02 2026-10-05 ok
*.3cx.com 19 2025-06-18 2026-09-28 —
team.3cx.com 3 2025-09-15 2026-08-25 ok
corp.3cx.com 1 2026-04-16 2026-04-16 nodata
*.corp.3cx.com 2 2026-04-16 2026-09-24 —
ops.3cx.com 5 2026-05-16 2026-09-13 ok
www.3cx.com 4 2026-06-06 2026-10-05 ok

Programmatic access, with DNS A records: API GET /v1/hosts/3cx.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/3cx.com.