Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts and first/last seen dates.

3 hosts · 169 ms

HostCertsFirst seenLast seen
nansec.se 1 2025-12-21 2025-12-21
mta-sts.nansec.se 2 2026-02-24 2026-07-12
www.nansec.se 1 2025-12-21 2025-12-21

Programmatic access: API GET /v1/hosts/nansec.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/nansec.se.