Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts, first/last seen and live DNS status.

6 hosts · 339 ms

HostCertsFirst seenLast seenDNS
safeharbor.com 26 2026-04-11 2026-10-05 ok
*.safeharbor.com 26 2026-04-11 2026-10-05 —
marketplace.safeharbor.com 11 2026-04-30 2026-09-07 ok
shop-stg.safeharbor.com 5 2026-05-02 2026-09-11 ok
portal.safeharbor.com 22 2026-04-30 2026-09-13 ok
mta-sts.safeharbor.com 1 2026-09-14 2026-09-14 ok

Programmatic access, with DNS A records: API GET /v1/hosts/safeharbor.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/safeharbor.com.