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 · 215 ms

HostCertsFirst seenLast seenDNS
gottman.com 4 2026-06-09 2026-10-07 ok
checkup.staging.gottman.com 1 2026-01-07 2026-01-07 ok
learning.gottman.com 16 2026-04-18 2026-08-15 ok
submit-spark-email-events-agg.spark-ui.gottman.com 3 2026-06-04 2026-08-03 ok
image.mail.gottman.com 1 2026-06-13 2026-06-13 ok
cdn.gottman.com 1 2025-07-24 2025-07-24 nxdomain
learn.gottman.com 22 2026-05-23 2026-09-18 ok
info.gottman.com 10 2026-06-06 2026-10-03 ok
checkup.gottman.com 1 2026-01-12 2026-01-12 ok
ec2-3-15-144-180.checkup.gottman.com 7 2026-04-30 2026-09-29 ok
www.checkup.gottman.com 1 2026-01-12 2026-01-12 ok
support.gottman.com 4 2026-04-20 2026-08-18 ok
airflow.gottman.com 4 2026-04-11 2026-08-09 ok
www.gottman.com 14 2026-05-07 2026-10-07 ok

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