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.

2 hosts · 293 ms

HostCertsFirst seenLast seenDNS
email.gearjunkie.com 14 2026-04-18 2026-08-15 ok
elink80a.email.gearjunkie.com 14 2026-04-10 2026-08-06 ok

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