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.

8 hosts · 308 ms

HostCertsFirst seenLast seenDNS
orttu.com 26 2026-05-15 2026-09-28 ok
*.orttu.com 12 2025-09-24 2026-09-26 —
i.orttu.com 3 2026-05-23 2026-09-12 ok
click.orttu.com 10 2026-05-10 2026-09-05 ok
app.orttu.com 8 2026-05-04 2026-07-03 ok
returns.orttu.com 8 2026-05-15 2026-09-10 ok
account.orttu.com 13 2026-04-13 2026-09-26 ok
www.orttu.com 15 2026-05-16 2026-09-27 ok

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