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.

14 hosts · 309 ms

HostCertsFirst seenLast seenDNS
sco.edu 25 2026-04-14 2026-09-30 ok
*.sco.edu 21 2026-04-17 2026-09-30 —
hvac.sco.edu 1 2026-02-26 2026-02-26 ok
www.hvac.sco.edu 1 2026-02-26 2026-02-26 nxdomain
tec.sco.edu 5 2026-04-22 2026-08-20 ok
shop.tec.sco.edu 13 2026-06-05 2026-10-02 ok
www.tec.sco.edu 5 2026-04-22 2026-08-20 ok
opc.sco.edu 5 2026-05-16 2026-09-14 ok
moodle.sco.edu 4 2026-04-13 2026-08-11 ok
explore.sco.edu 2 2025-10-14 2026-09-28 ok
email.rgrp.sco.edu 5 2026-05-12 2026-09-09 ok
mta-sts.sco.edu 4 2026-04-17 2026-08-15 ok
www.sco.edu 4 2026-04-14 2026-08-12 ok
library.sco.edu 5 2026-05-24 2026-09-23 ok

Programmatic access, with DNS A records: API GET /v1/hosts/sco.edu (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/sco.edu.