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 · 213 ms

HostCertsFirst seenLast seenDNS
hegnar.info 4 2026-05-04 2026-09-01 ok
email.mail.hegnar.info 5 2026-05-08 2026-09-05 ok
email.hegnar.info 5 2026-04-24 2026-08-22 ok
www.hegnar.info 4 2026-05-04 2026-09-01 ok

Programmatic access, with DNS A records: API GET /v1/hosts/hegnar.info (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/hegnar.info.