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.

5 hosts · 238 ms

HostCertsFirst seenLast seenDNS
quadlockcase.ca 11 2026-05-14 2026-09-22 ok
clk.quadlockcase.ca 2 2026-10-04 2026-10-04 ok
sms.quadlockcase.ca 10 2026-05-10 2026-09-06 ok
account.quadlockcase.ca 16 2026-04-11 2026-10-07 ok
www.quadlockcase.ca 11 2026-05-14 2026-09-23 ok

Programmatic access, with DNS A records: API GET /v1/hosts/quadlockcase.ca (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/quadlockcase.ca.