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.

13 hosts · 302 ms

HostCertsFirst seenLast seenDNS
tomnehl.com 23 2026-04-21 2026-09-27 ok
*.tomnehl.com 14 2026-04-27 2026-09-27 —
link.tomnehl.com 5 2026-05-08 2026-09-05 ok
helpdesk.tomnehl.com 8 2026-05-31 2026-09-26 ok
vpn.tomnehl.com 21 2026-02-27 2026-10-05 ok
www.vpn.tomnehl.com 5 2026-02-27 2026-08-31 nxdomain
go.tomnehl.com 3 2026-09-23 2026-09-23 ok
b2phones.tomnehl.com 10 2026-04-22 2026-08-19 ok
b3phones.tomnehl.com 12 2026-04-21 2026-08-17 ok
b4phones.tomnehl.com 8 2026-04-20 2026-08-16 ok
parts.tomnehl.com 5 2026-06-03 2026-08-07 ok
mta-sts.tomnehl.com 8 2026-04-13 2026-08-11 ok
www.tomnehl.com 10 2026-04-21 2026-08-17 ok

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