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.

3 hosts · 245 ms

HostCertsFirst seenLast seenDNS
memo-i.com 13 2026-04-17 2026-09-29 ok
support.memo-i.com 4 2026-05-02 2026-10-02 ok
www.memo-i.com 13 2026-04-17 2026-09-29 ok

Programmatic access, with DNS A records: API GET /v1/hosts/memo-i.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/memo-i.com.