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.

12 hosts · 336 ms

HostCertsFirst seenLast seenDNS
exchangemaster.ch 16 2026-02-17 2026-09-17 ok
*.exchangemaster.ch 14 2026-05-02 2026-09-17 —
office365.exchangemaster.ch 1 2026-05-01 2026-05-01 nxdomain
kb.exchangemaster.ch 1 2026-05-01 2026-05-01 ok
portal.exchangemaster.ch 1 2026-05-01 2026-05-01 ok
mail.exchangemaster.ch 1 2026-05-01 2026-05-01 ok
crm.exchangemaster.ch 28 2026-05-19 2026-06-16 ok
scanner.exchangemaster.ch 1 2025-09-27 2025-09-27 nxdomain
mta-sts.exchangemaster.ch 3 2026-05-16 2026-10-06 ok
support.exchangemaster.ch 25 2026-08-26 2026-09-30 ok
www.exchangemaster.ch 1 2026-03-18 2026-03-18 ok
pbx.exchangemaster.ch 5 2026-05-05 2026-09-18 ok

Programmatic access, with DNS A records: API GET /v1/hosts/exchangemaster.ch (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/exchangemaster.ch.