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 · 229 ms

HostCertsFirst seenLast seen
resurs.fi 4 2025-07-30 2026-09-01
*.resurs.fi 2 2026-04-01 2026-09-01
www.resurs.fi 4 2025-07-30 2026-09-09

Programmatic access: API GET /v1/hosts/resurs.fi (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/resurs.fi.