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 · 187 ms

HostCertsFirst seenLast seenDNS
bsn.se 3 2025-12-04 2026-09-18 ok
link.bsn.se 5 2026-05-09 2026-09-06 ok
en.bsn.se 4 2026-04-13 2026-08-11 ok
www.bsn.se 3 2025-12-04 2026-09-18 ok

Programmatic access, with DNS A records: API GET /v1/hosts/bsn.se (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/bsn.se.