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.

5 hosts · 224 ms

HostCertsFirst seenLast seen
opticontacts.com 19 2026-05-26 2026-10-04
*.opticontacts.com 19 2026-05-26 2026-10-04
i.opticontacts.com 3 2026-05-18 2026-09-04
help.opticontacts.com 8 2026-05-09 2026-09-04
*.camp.opticontacts.com 5 2026-05-20 2026-09-17

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