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.

4 hosts · 253 ms

HostCertsFirst seenLast seenDNS
quadlock.com.au 3 2026-06-10 2026-08-09 ok
*.quadlock.com.au 3 2026-06-10 2026-08-09 —
cx-training-sim.quadlock.com.au 14 2026-06-08 2026-10-04 ok
agent-assistant.quadlock.com.au 5 2026-06-05 2026-10-04 ok

Programmatic access, with DNS A records: API GET /v1/hosts/quadlock.com.au (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/quadlock.com.au.