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 · 254 ms

HostCertsFirst seenLast seenDNS
relier.com 17 2026-04-23 2026-09-17 ok
*.relier.com 10 2026-04-27 2026-09-17 —
link.relier.com 6 2026-06-02 2026-09-30 ok
preview.relier.com 3 2026-06-08 2026-08-09 ok
www.relier.com 7 2026-04-23 2026-09-05 ok

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