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.

4 hosts · 270 ms

HostCertsFirst seenLast seen
ssls.cz 11 2026-03-23 2026-09-27
*.ssls.cz 2 2026-03-23 2026-09-24
cron.ssls.cz 3 2026-05-22 2026-08-12
www.ssls.cz 9 2026-07-04 2026-09-27

Programmatic access: API GET /v1/hosts/ssls.cz (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/ssls.cz.