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.

8 hosts · 300 ms

HostCertsFirst seenLast seenDNS
sepura.com 8 2025-09-01 2026-09-14 ok
*.sepura.com 3 2025-09-01 2026-09-14 —
owa.sepura.com 1 2025-11-12 2025-11-12 nxdomain
ic.sepura.com 2 2026-09-03 2026-09-04 ok
www.ic.sepura.com 1 2026-09-04 2026-09-04 ok
autodiscover.sepura.com 1 2025-11-12 2025-11-12 ok
mta-sts.sepura.com 5 2026-05-19 2026-09-15 ok
www.sepura.com 5 2026-04-25 2026-08-25 ok

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