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 · 236 ms

HostCertsFirst seenLast seenDNS
geiglesafety.com 6 2026-05-10 2026-09-06 ok
fgt60f2024hq.geiglesafety.com 5 2026-05-11 2026-09-08 ok
www.geiglesafety.com 6 2026-05-10 2026-09-06 ok

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