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.

7 hosts · 321 ms

HostCertsFirst seenLast seenDNS
recordquest.com 5 2026-05-10 2026-09-09 ok
f.recordquest.com 2 2026-01-05 2026-01-05 ok
www.f.recordquest.com 2 2026-01-05 2026-01-05 nxdomain
app.recordquest.com 1 2025-12-10 2025-12-10 ok
apptest.recordquest.com 2 2025-07-25 2026-08-13 ok
dev.recordquest.com 5 2026-05-22 2026-09-20 ok
www.recordquest.com 5 2026-05-10 2026-09-09 ok

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