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.

4 hosts · 342 ms

HostCertsFirst seenLast seenDNS
acrelief.com 17 2026-02-16 2026-09-21 ok
*.acrelief.com 20 2026-02-15 2026-09-21 —
go.acrelief.com 5 2026-04-25 2026-09-10 ok
links.acrelief.com 5 2026-05-03 2026-09-02 ok

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