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.

7 hosts · 295 ms

HostCertsFirst seenLast seen
guardia.school 2 2025-06-18 2026-05-18
*.guardia.school 2 2025-06-18 2026-05-18
tracking.guardia.school 3 2026-05-25 2026-09-09
sherlock.guardia.school 3 2026-05-10 2026-08-30
wordpress.guardia.school 5 2026-05-03 2026-09-01
hubspot.guardia.school 10 2026-04-23 2026-08-19
www.guardia.school 5 2026-05-28 2026-09-25

Programmatic access: API GET /v1/hosts/guardia.school (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/guardia.school.