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.

20 hosts · 367 ms

HostCertsFirst seenLast seenDNS
bluebit.vn 83 2025-06-10 2026-10-01 ok
*.bluebit.vn 14 2025-06-18 2026-10-01 —
test1.bluebit.vn 1 2026-07-15 2026-07-15 nxdomain
nghia.bluebit.vn 3 2026-06-12 2026-09-22 nxdomain
acb.bluebit.vn 2 2026-03-19 2026-04-06 nxdomain
abc.bluebit.vn 2 2026-06-12 2026-06-24 nxdomain
backend.bluebit.vn 3 2025-07-07 2026-08-10 ok
apache.bluebit.vn 1 2026-07-21 2026-07-21 nxdomain
tech.bluebit.vn 5 2026-06-22 2026-07-07 nxdomain
api.bluebit.vn 8 2025-07-07 2026-08-10 ok
keytalk.bluebit.vn 1 2026-04-08 2026-04-08 ok
technical.bluebit.vn 1 2026-07-07 2026-07-07 nxdomain
sn.bluebit.vn 1 2026-07-02 2026-07-02 nxdomain
demo.bluebit.vn 3 2026-04-06 2026-07-24 nxdomain
keytalk-uat.bluebit.vn 1 2026-07-15 2026-07-15 nxdomain
test.bluebit.vn 3 2026-04-06 2026-07-02 nxdomain
acmetest.bluebit.vn 1 2026-07-07 2026-07-07 ok
www.bluebit.vn 43 2025-06-19 2026-09-17 ok
nginx.bluebit.vn 1 2026-07-23 2026-07-23 nxdomain
xyz.bluebit.vn 1 2026-06-12 2026-06-12 nxdomain

Programmatic access, with DNS A records: API GET /v1/hosts/bluebit.vn (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/bluebit.vn.