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 · 206 ms

HostCertsFirst seenLast seenDNS
mail.kbcbrussels.be 1 2025-12-08 2025-12-08 ok
m.mail.kbcbrussels.be 1 2025-12-08 2025-12-08 ok
res.mail.kbcbrussels.be 1 2025-12-08 2025-12-08 ok
t.mail.kbcbrussels.be 1 2025-12-08 2025-12-08 ok
www.mail.kbcbrussels.be 1 2025-12-08 2025-12-08 nxdomain

Programmatic access, with DNS A records: API GET /v1/hosts/mail.kbcbrussels.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/mail.kbcbrussels.be.