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 · 271 ms

HostCertsFirst seenLast seenDNS
bonfire-mail.com 1 2026-03-26 2026-03-26 ok
email.m.bonfire-mail.com 1 2026-07-25 2026-07-25 ok
email.hello.bonfire-mail.com 1 2026-07-24 2026-07-24 ok

Programmatic access, with DNS A records: API GET /v1/hosts/bonfire-mail.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/bonfire-mail.com.