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.

6 hosts · 291 ms

HostCertsFirst seenLast seenDNS
dfs.ca 5 2025-08-29 2026-08-04 ok
11197405.dfs.ca 11 2025-11-12 2026-08-27 ok
url4109.dfs.ca 3 2025-09-10 2026-07-14 ok
m.dfs.ca 3 2025-09-11 2026-07-14 ok
www.m.dfs.ca 3 2025-09-11 2026-07-14 ok
www.dfs.ca 3 2025-09-11 2026-07-14 ok

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