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.

12 hosts · 225 ms

HostCertsFirst seenLast seen
cecil.nl 14 2026-02-16 2026-09-13
mxa.cecil.nl 12 2026-02-16 2026-09-24
integ-bc.cecil.nl 10 2026-05-04 2026-08-30
prod.cecil.nl 8 2026-05-04 2026-08-30
irl.prod.cecil.nl 7 2026-04-17 2026-08-13
autodiscover.customerservice.cecil.nl 10 2026-05-11 2026-09-09
integ.cecil.nl 10 2026-05-04 2026-08-30
ssgtm.cecil.nl 12 2026-04-25 2026-08-22
integ.ssgtm.cecil.nl 10 2026-04-22 2026-08-19
autodiscover.cecil.nl 10 2026-05-11 2026-09-09
dev.cecil.nl 10 2026-04-21 2026-08-17
www.cecil.nl 12 2026-02-16 2026-09-13

Programmatic access: API GET /v1/hosts/cecil.nl (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/cecil.nl.