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.

9 hosts · 365 ms

HostCertsFirst seenLast seenDNS
unit8.com 12 2026-05-03 2026-08-30 ok
more.unit8.com 13 2026-05-18 2026-09-14 ok
radar.unit8.com 4 2026-04-19 2026-08-17 ok
darts.unit8.com 14 2026-05-29 2026-09-24 ok
www.darts.unit8.com 20 2026-05-29 2026-09-25 ok
mta-sts.unit8.com 2 2026-06-09 2026-08-19 ok
meet.unit8.com 2 2026-02-26 2026-06-18 ok
www.meet.unit8.com 2 2026-02-26 2026-06-18 ok
www.unit8.com 13 2026-05-02 2026-08-28 ok

Programmatic access, with DNS A records: API GET /v1/hosts/unit8.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/unit8.com.