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.

7 hosts · 237 ms

HostCertsFirst seenLast seenDNS
athleta.ca 6 2026-03-10 2026-08-18 ok
cloud.email.athleta.ca 2 2026-04-25 2026-09-28 ok
image.email.athleta.ca 5 2026-03-05 2026-08-31 ok
click.email.athleta.ca 3 2026-04-24 2026-09-25 ok
view.email.athleta.ca 3 2026-04-18 2026-09-19 ok
cp.athleta.ca 9 2026-04-09 2026-09-20 ok
www.athleta.ca 5 2026-03-10 2026-08-05 ok

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