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.

8 hosts · 230 ms

Download CSV
HostCertsFirst seenLast seen
springfieldcollege.edu 5 2026-05-03 2026-10-03
sccollege.springfieldcollege.edu 1 2025-09-14 2025-09-14
leopard.sccollege.springfieldcollege.edu 1 2025-09-14 2025-09-14
panther.sccollege.springfieldcollege.edu 1 2025-09-14 2025-09-14
admaster.springfieldcollege.edu 1 2025-09-14 2025-09-14
papercut.springfieldcollege.edu 1 2025-08-17 2025-08-17
www.springfieldcollege.edu 4 2026-06-05 2026-10-03
tawny.springfieldcollege.edu 1 2025-10-14 2025-10-14

Programmatic access: API GET /v1/hosts/springfieldcollege.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/springfieldcollege.edu.