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.

4 hosts · 329 ms

HostCertsFirst seenLast seenDNS
ads.google.com 157 2026-04-20 2026-10-05 ok
frame.ads.google.com 157 2026-04-20 2026-10-05 nxdomain
*.frame.ads.google.com 157 2026-04-20 2026-10-05 —
www.ads.google.com 157 2026-04-20 2026-10-05 ok

Programmatic access, with DNS A records: API GET /v1/hosts/ads.google.com (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/ads.google.com.