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 · 221 ms

HostCertsFirst seenLast seen
leadertelecom.nl 4 2025-08-07 2026-08-20
*.leadertelecom.nl 5 2025-08-07 2026-08-20
smb2.leadertelecom.nl 5 2026-05-06 2026-09-03
st.smb2.leadertelecom.nl 5 2026-05-14 2026-09-11
librenms2.leadertelecom.nl 4 2026-04-19 2026-08-17
st.filter.leadertelecom.nl 5 2026-05-14 2026-09-11
mattermost.leadertelecom.nl 4 2026-04-21 2026-08-20

Programmatic access: API GET /v1/hosts/leadertelecom.nl (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/leadertelecom.nl.