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.

13 hosts · 240 ms

HostCertsFirst seenLast seenDNS
c-date.de 7 2026-04-21 2026-09-03 ok
pic.c-date.de 2 2025-07-17 2026-06-29 ok
stc.c-date.de 3 2026-03-05 2026-06-30 ok
pic.stage.c-date.de 2 2025-07-09 2026-06-29 ok
stc.stage.c-date.de 4 2026-03-05 2026-06-30 ok
pcon.stage.c-date.de 3 2025-07-10 2026-06-30 ok
mail.c-date.de 4 2026-04-21 2026-08-19 ok
crm.c-date.de 6 2025-07-24 2026-07-08 ok
pcon.c-date.de 2 2025-07-16 2026-06-30 ok
test.c-date.de 6 2026-04-21 2026-09-04 ok
www.c-date.de 12 2026-04-15 2026-08-19 ok
unstable.www.c-date.de 4 2026-04-21 2026-08-19 ok
test.www.c-date.de 26 2026-04-21 2026-09-20 ok

Programmatic access, with DNS A records: API GET /v1/hosts/c-date.de (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/c-date.de.