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.

7 hosts · 562 ms

HostCertsFirst seenLast seenDNS
oysi.gmbh 13 2026-05-14 2026-09-23 ok
*.oysi.gmbh 8 2026-05-28 2026-09-23 —
shop.oysi.gmbh 5 2026-05-17 2026-09-15 nxdomain
dpp.oysi.gmbh 5 2026-05-14 2026-09-11 ok
erp.oysi.gmbh 5 2026-05-18 2026-09-16 nxdomain
mta-sts.oysi.gmbh 16 2026-05-15 2026-10-01 ok
www.oysi.gmbh 5 2026-05-14 2026-09-11 ok

Programmatic access, with DNS A records: API GET /v1/hosts/oysi.gmbh (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/oysi.gmbh.