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 · 292 ms

HostCertsFirst seenLast seenDNS
onlyny.com 15 2026-05-15 2026-09-25 ok
account.onlyny.com 15 2026-05-06 2026-09-15 ok
www.onlyny.com 15 2026-05-15 2026-09-24 ok
pay.onlyny.com 1 2026-05-08 2026-05-08 ok
www.pay.onlyny.com 1 2026-05-08 2026-05-08 nxdomain

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