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.

5 hosts · 336 ms

HostCertsFirst seenLast seenDNS
johansens.com 16 2026-04-28 2026-08-24 ok
c.johansens.com 5 2025-12-29 2025-12-29 ok
qc.johansens.com 10 2025-09-23 2026-08-24 ok
link.johansens.com 4 2026-04-15 2026-08-13 ok
www.johansens.com 16 2026-04-27 2026-08-23 ok

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