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.

16 hosts · 284 ms

HostCertsFirst seenLast seenDNS
hygi.de 8 2026-02-26 2026-10-05 ok
*.hygi.de 2 2026-04-30 2026-04-30 —
cdn2.hygi.de 6 2026-06-12 2026-08-19 ok
media.hygi.de 8 2026-06-12 2026-08-25 ok
ad.hygi.de 5 2026-05-06 2026-09-03 ok
*.ad.hygi.de 5 2026-05-06 2026-09-03 —
vzimbra.ad.hygi.de 10 2026-05-06 2026-09-06 nxdomain
webapi.hygi.de 6 2026-06-12 2026-08-19 ok
ark.hygi.de 5 2026-04-28 2026-08-26 ok
sark.hygi.de 5 2026-04-28 2026-08-26 ok
mail.hygi.de 5 2026-05-14 2026-09-13 ok
im.hygi.de 5 2026-04-28 2026-08-26 ok
cdn.hygi.de 9 2026-06-12 2026-08-25 ok
pnfkhu.hygi.de 3 2026-05-13 2026-09-21 ok
www.hygi.de 9 2026-02-26 2026-10-05 ok
index.hygi.de 5 2026-04-28 2026-08-26 ok

Programmatic access, with DNS A records: API GET /v1/hosts/hygi.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/hygi.de.