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.

11 hosts · 251 ms

HostCertsFirst seenLast seenDNS
lirr.org 37 2026-01-05 2026-10-01 ok
*.lirr.org 37 2026-01-05 2026-10-01 —
infoream1jamtad.lirr.org 11 2026-05-27 2026-09-23 ok
retiree.lirr.org 10 2026-05-20 2026-09-16 ok
onlinetraining.lirr.org 12 2026-05-14 2026-09-10 ok
camsmobiletrn.lirr.org 2 2026-08-27 2026-08-27 ok
autodiscover.lirr.org 1 2025-08-12 2025-08-12 ok
lirrgroupreservations.lirr.org 10 2026-05-14 2026-09-10 ok
eamdosdev.lirr.org 7 2026-05-31 2026-09-26 ok
crew.lirr.org 6 2026-04-10 2026-09-09 ok
www.lirr.org 5 2026-06-11 2026-09-09 ok

Programmatic access, with DNS A records: API GET /v1/hosts/lirr.org (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/lirr.org.