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.

2 hosts · 345 ms

HostCertsFirst seenLast seenDNS
emails.ancestry.ca 20 2026-04-14 2026-10-01 ok
*.emails.ancestry.ca 6 2026-06-04 2026-10-01 —

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