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.

4 hosts · 349 ms

HostCertsFirst seenLast seenDNS
crydercapital.com 7 2025-06-15 2026-10-04 ok
research.crydercapital.com 10 2026-05-25 2026-09-24 ok
mta-sts.crydercapital.com 2 2026-03-22 2026-08-22 ok
www.crydercapital.com 7 2025-06-15 2026-10-04 ok

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