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.

6 hosts · 327 ms

HostCertsFirst seenLast seenDNS
tsubaki.com 2 2026-04-23 2026-06-30 ok
*.tsubaki.com 1 2026-06-30 2026-06-30 —
brand.tsubaki.com 5 2026-05-05 2026-09-02 ok
stg.tsubaki.com 5 2026-05-25 2026-09-22 ok
twins.tsubaki.com 8 2026-05-06 2026-09-01 ok
www.tsubaki.com 1 2026-04-23 2026-04-23 ok

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