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.

18 hosts · 291 ms

HostCertsFirst seenLast seenDNS
bigspeak.com 1 2025-12-23 2025-12-23 ok
*.bigspeak.com 1 2025-12-23 2025-12-23 —
sand1.bigspeak.com 1 2026-01-05 2026-01-05 nodata
*.sand1.bigspeak.com 1 2026-01-05 2026-01-05 —
abc.bigspeak.com 3 2025-09-21 2026-08-22 nodata
*.abc.bigspeak.com 3 2025-09-21 2026-08-22 —
sand.bigspeak.com 2 2025-10-27 2026-09-27 nodata
*.sand.bigspeak.com 2 2025-10-27 2026-09-27 —
edge.bigspeak.com 1 2025-11-10 2025-11-10 nodata
*.edge.bigspeak.com 1 2025-11-10 2025-11-10 —
go.bigspeak.com 10 2026-04-28 2026-09-25 ok
foo.bigspeak.com 2 2025-09-11 2026-08-12 ok
*.foo.bigspeak.com 2 2025-09-11 2026-08-12 —
event.bigspeak.com 1 2025-11-27 2025-11-27 ok
www.event.bigspeak.com 1 2025-11-27 2025-11-27 ok
bigagency.bigspeak.com 7 2026-06-01 2026-10-01 ok
xyz.bigspeak.com 3 2025-09-07 2026-08-08 nodata
*.xyz.bigspeak.com 3 2025-09-07 2026-08-08 —

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