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.

20 hosts · 249 ms

HostCertsFirst seenLast seen
geocerts.com 6 2025-10-21 2026-08-25
*.geocerts.com 1 2026-08-07 2026-08-07
persistent-071626-0931.geocerts.com 1 2026-07-16 2026-07-16
persistent-division-713881.geocerts.com 1 2026-07-18 2026-07-18
san1.geocerts.com 1 2026-08-07 2026-08-07
sub1.sub2.geocerts.com 2 2026-08-07 2026-08-19
route53.geocerts.com 9 2026-06-19 2026-06-23
www.route53.geocerts.com 2 2026-06-23 2026-06-23
persistent-division-376283.geocerts.com 1 2026-07-18 2026-07-18
persistent-071526-1705.geocerts.com 1 2026-07-16 2026-07-16
extra.geocerts.com 2 2026-08-23 2026-08-25
sub.geocerts.com 3 2026-07-16 2026-07-18
ecc.geocerts.com 6 2026-06-23 2026-08-19
edge.geocerts.com 2 2026-03-20 2026-08-20
elb.edge.geocerts.com 2 2026-03-11 2026-07-27
log.geocerts.com 3 2026-07-16 2026-07-18
go.geocerts.com 1 2026-08-12 2026-08-12
persistent.geocerts.com 1 2026-07-16 2026-07-16
www.geocerts.com 6 2025-10-21 2026-08-25
elb.www.geocerts.com 2 2026-03-20 2026-08-20

Programmatic access: API GET /v1/hosts/geocerts.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/geocerts.com.