Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts and first/last seen dates.

12 hosts · 234 ms

HostCertsFirst seenLast seen
gtm.com 12 2025-12-10 2026-09-20
*.gtm.com 8 2025-12-10 2026-09-20
freequote.gtm.com 15 2026-05-08 2026-09-04
devhh.gtm.com 5 2026-05-09 2026-09-08
mail.gtm.com 6 2026-03-07 2026-10-07
www.mail.gtm.com 6 2026-03-07 2026-10-07
email.gtm.com 18 2026-06-08 2026-10-04
vpn.gtm.com 5 2025-08-14 2026-09-01
www.vpn.gtm.com 5 2025-08-14 2026-09-01
autodiscover.gtm.com 2 2026-04-23 2026-10-07
pages.gtm.com 13 2026-06-08 2026-10-05
www.gtm.com 4 2026-04-16 2026-08-16

Programmatic access: API GET /v1/hosts/gtm.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/gtm.com.