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.

3 hosts · 274 ms

HostCertsFirst seenLast seenDNS
d.eml.ruthschris.com 14 2026-05-06 2026-09-01 ok
e.eml.ruthschris.com 10 2026-05-06 2026-09-01 ok
se.eml.ruthschris.com 16 2026-05-07 2026-09-02 ok

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