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
engie.sk 4 2026-04-15 2026-08-12
test.engie.sk 5 2026-06-02 2026-09-28
www.engie.sk 4 2026-04-15 2026-08-12

Programmatic access: API GET /v1/hosts/engie.sk (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/engie.sk.