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.

25 hosts · 332 ms

HostCertsFirst seenLast seenDNS
cerby.com 4 2025-12-05 2026-08-10 ok
*.cerby.com 9 2025-12-28 2026-09-28 —
ca.cerby.com 5 2026-04-02 2026-09-14 nodata
*.ca.cerby.com 5 2026-04-02 2026-09-14 —
*.auth.ca.cerby.com 1 2026-04-28 2026-04-28 —
go.cerby.com 8 2026-05-04 2026-08-30 ok
hello.cerby.com 5 2026-05-09 2026-08-18 ok
oktademo.cerby.com 9 2026-04-14 2026-09-16 ok
help.cerby.com 10 2026-04-23 2026-08-20 ok
register.cerby.com 4 2026-04-11 2026-08-09 ok
*.tools.cerby.com 2 2025-10-07 2026-09-07 —
atlantis-asia.tools.cerby.com 1 2026-02-05 2026-02-05 ok
atlantis.tools.cerby.com 2 2026-03-11 2026-07-27 ok
atlantis-enterprise-agent.tools.cerby.com 2 2025-09-22 2026-08-23 ok
security-dev.tools.cerby.com 1 2026-03-21 2026-03-21 nodata
security.tools.cerby.com 3 2026-03-21 2026-08-21 ok
agents.cerby.com 2 2026-08-11 2026-08-11 ok
*.agents.cerby.com 2 2026-08-11 2026-08-11 —
status.cerby.com 8 2026-05-06 2026-09-20 ok
connect.cerby.com 5 2026-05-12 2026-09-14 ok
support.cerby.com 5 2026-05-25 2026-09-25 ok
trust.cerby.com 20 2026-04-27 2026-08-24 ok
www.cerby.com 12 2026-05-01 2026-08-28 ok
styx.cerby.com 1 2026-09-22 2026-09-22 ok
auth-proxy.cerby.com 10 2026-04-30 2026-08-27 ok

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