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.

30 hosts · 270 ms

HostCertsFirst seenLast seenDNS
gecu.com 15 2026-01-31 2026-09-23 ok
*.gecu.com 1 2026-01-31 2026-01-31 —
vpn2.gecu.com 11 2025-08-23 2026-09-17 ok
www.vpn2.gecu.com 11 2025-08-23 2026-09-17 nxdomain
wsa.gecu.com 4 2025-10-22 2026-08-23 nxdomain
www.wsa.gecu.com 4 2025-10-22 2026-08-23 nxdomain
prod.gecu.com 10 2026-05-10 2026-09-05 ok
cloud.gecu.com 1 2026-09-30 2026-09-30 ok
mortgage.gecu.com 6 2026-05-01 2026-08-21 ok
image.gecu.com 5 2026-10-01 2026-10-03 ok
pre.gecu.com 8 2026-04-19 2026-08-15 ok
link.gecu.com 1 2026-09-30 2026-09-30 ok
mail.gecu.com 1 2025-10-30 2025-10-30 ok
www.mail.gecu.com 1 2025-10-30 2025-10-30 nxdomain
exmail.gecu.com 8 2025-08-02 2026-08-16 ok
www.exmail.gecu.com 8 2025-08-02 2026-08-16 nxdomain
m.gecu.com 1 2025-12-11 2025-12-11 ok
vpn.gecu.com 8 2025-08-23 2026-09-17 ok
www.vpn.gecu.com 8 2025-08-23 2026-09-17 nxdomain
mycoop.gecu.com 3 2025-07-09 2026-07-10 nxdomain
www.mycoop.gecu.com 3 2025-07-09 2026-07-10 nxdomain
member.gecu.com 2 2025-10-01 2026-09-01 ok
historybrowser.gecu.com 2 2026-09-14 2026-09-14 ok
autodiscover.gecu.com 8 2025-08-02 2026-08-16 ok
cardrewards.gecu.com 5 2026-05-31 2026-09-28 ok
intranet.gecu.com 1 2025-10-02 2025-10-02 ok
int.gecu.com 8 2026-04-19 2026-08-15 ok
view.gecu.com 2 2026-08-28 2026-08-28 ok
www.gecu.com 15 2026-05-27 2026-09-22 ok
my.gecu.com 5 2026-05-26 2026-09-24 ok

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