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.

3 hosts · 297 ms

HostCertsFirst seenLast seenDNS
bisonbank.com 3 2025-09-25 2026-09-18 ok
*.bisonbank.com 3 2025-09-25 2026-09-18 —
events.bisonbank.com 1 2026-09-24 2026-09-24 ok

Programmatic access, with DNS A records: API GET /v1/hosts/bisonbank.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/bisonbank.com.