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 · 308 ms

HostCertsFirst seenLast seenDNS
peakefederal.com 21 2026-05-05 2026-09-20 ok
*.peakefederal.com 16 2026-05-25 2026-09-20 —
sta.peakefederal.com 5 2026-05-05 2026-09-04 ok
maintenance.peakefederal.com 7 2026-05-12 2026-10-01 ok
online.peakefederal.com 16 2026-06-03 2026-10-06 ok
archive.peakefederal.com 3 2026-06-09 2026-08-09 ok
dev.peakefederal.com 5 2026-05-09 2026-09-08 ok
www.peakefederal.com 5 2026-05-05 2026-09-04 ok

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