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 · 275 ms

HostCertsFirst seenLast seenDNS
lm3x.com 13 2026-04-25 2026-09-17 ok
*.lm3x.com 8 2026-04-25 2026-09-17 —
file.lm3x.com 9 2026-04-17 2026-09-29 ok
cdn.lm3x.com 8 2026-05-08 2026-09-17 ok
www.lm3x.com 5 2026-05-16 2026-09-16 ok

Programmatic access, with DNS A records: API GET /v1/hosts/lm3x.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/lm3x.com.