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.

7 hosts · 336 ms

HostCertsFirst seenLast seenDNS
springtimeinc.com 2 2026-05-05 2026-10-05 ok
remote.springtimeinc.com 2 2025-08-06 2026-07-31 ok
www.remote.springtimeinc.com 2 2025-08-06 2026-07-31 nxdomain
elink.springtimeinc.com 15 2026-04-14 2026-09-30 ok
webmail.springtimeinc.com 2 2026-05-05 2026-10-05 ok
www.springtimeinc.com 3 2025-12-05 2026-10-05 ok
delivery.springtimeinc.com 3 2026-05-24 2026-09-10 ok

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