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.

9 hosts · 255 ms

HostCertsFirst seenLast seenDNS
tsubaki.cz 4 2025-07-10 2026-08-11 ok
office.tsubaki.cz 5 2026-04-26 2026-08-24 ok
en.tsubaki.cz 4 2025-07-10 2026-08-11 ok
dev.en.tsubaki.cz 4 2026-05-05 2026-07-04 ok
www.en.tsubaki.cz 1 2025-07-10 2025-07-10 ok
mta-sts.tsubaki.cz 5 2026-05-05 2026-09-02 ok
www.mta-sts.tsubaki.cz 5 2026-05-05 2026-09-02 ok
dev.tsubaki.cz 4 2026-05-05 2026-07-04 ok
www.tsubaki.cz 4 2025-07-10 2026-08-11 ok

Programmatic access, with DNS A records: API GET /v1/hosts/tsubaki.cz (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/tsubaki.cz.