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.

10 hosts · 228 ms

HostCertsFirst seenLast seenDNS
acoss.fr 3 2026-03-18 2026-09-30 ok
*.acoss.fr 3 2026-03-18 2026-09-30 —
mft1.acoss.fr 2 2026-03-25 2026-09-21 nxdomain
mft2.acoss.fr 2 2026-03-25 2026-09-21 nxdomain
collab-edge.acoss.fr 1 2025-12-16 2025-12-16 nxdomain
jabber.acoss.fr 1 2025-12-16 2025-12-16 ok
snt.acoss.fr 1 2026-06-04 2026-06-04 ok
www.snt.acoss.fr 1 2026-06-04 2026-06-04 nxdomain
mftdev.acoss.fr 2 2026-03-25 2026-09-21 nxdomain
www.mftdev.acoss.fr 2 2026-03-25 2026-09-21 nxdomain

Programmatic access, with DNS A records: API GET /v1/hosts/acoss.fr (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/acoss.fr.