Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts and first/last seen dates.

7 hosts · 247 ms

HostCertsFirst seenLast seen
hsc.on.ca 13 2025-09-25 2026-10-05
*.hsc.on.ca 6 2025-09-25 2026-10-07
galleries.hsc.on.ca 10 2026-05-07 2026-09-02
publications.hsc.on.ca 3 2026-04-23 2026-08-21
radius.hsc.on.ca 3 2025-09-19 2026-10-08
www.radius.hsc.on.ca 2 2025-09-19 2026-10-08
www.hsc.on.ca 2 2025-07-28 2026-06-28

Programmatic access: API GET /v1/hosts/hsc.on.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/hsc.on.ca.