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.

7 hosts · 321 ms

HostCertsFirst seenLast seenDNS
idaoffice.org 13 2026-05-21 2026-09-27 ok
*.idaoffice.org 8 2026-05-21 2026-09-16 —
blog.idaoffice.org 3 2026-06-10 2026-08-09 ok
agent-api.idaoffice.org 5 2026-05-30 2026-09-27 ok
admin.idaoffice.org 8 2026-05-30 2026-10-01 ok
agent-widget.idaoffice.org 1 2026-09-21 2026-09-21 ok
management.idaoffice.org 5 2026-05-30 2026-09-27 ok

Programmatic access, with DNS A records: API GET /v1/hosts/idaoffice.org (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/idaoffice.org.