Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts and first/last seen dates.

6 hosts · 207 ms

HostCertsFirst seenLast seen
dustin.fi 8 2026-04-19 2026-08-15
*.dustin.fi 8 2026-04-19 2026-08-15
pin.dustin.fi 5 2026-05-21 2026-09-18
securecookiesdustininfo.dustin.fi 7 2026-05-01 2026-09-18
jobs.dustin.fi 4 2026-04-16 2026-08-14
securecookies.dustin.fi 5 2026-04-16 2026-09-03

Programmatic access: API GET /v1/hosts/dustin.fi (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/dustin.fi.