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.

8 hosts · 322 ms

HostCertsFirst seenLast seenDNS
rosyblue.be 19 2026-01-26 2026-09-26 ok
*.rosyblue.be 19 2026-01-26 2026-09-26 —
fantasyapi.rosyblue.be 1 2026-05-18 2026-05-18 ok
www.fantasyapi.rosyblue.be 1 2026-05-18 2026-05-18 nxdomain
reports.rosyblue.be 4 2025-06-23 2026-07-27 ok
www.reports.rosyblue.be 2 2025-06-23 2026-07-27 nxdomain
fantasy.rosyblue.be 1 2026-05-18 2026-05-18 ok
www.fantasy.rosyblue.be 1 2026-05-18 2026-05-18 nxdomain

Programmatic access, with DNS A records: API GET /v1/hosts/rosyblue.be (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/rosyblue.be.