Find every subdomain
of a domain.

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

3 hosts · 289 ms

HostCertsFirst seenLast seen
sigep.net 5 2026-05-23 2026-10-06
go.sigep.net 10 2026-04-20 2026-09-17
www.sigep.net 5 2026-05-23 2026-10-06

Programmatic access: API GET /v1/hosts/sigep.net (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/sigep.net.