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.

5 hosts · 314 ms

HostCertsFirst seenLast seenDNS
reddsflies.com 18 2026-05-20 2026-09-30 ok
go.reddsflies.com 11 2026-05-29 2026-09-25 ok
www.reddsflies.com 17 2026-05-20 2026-09-29 ok
pay.reddsflies.com 2 2026-04-14 2026-06-14 ok
www.pay.reddsflies.com 2 2026-04-14 2026-06-14 nxdomain

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