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.

8 hosts · 239 ms

HostCertsFirst seenLast seenDNS
signzy.com 6 2026-06-01 2026-10-04 ok
*.signzy.com 2 2026-09-01 2026-09-01 —
demo.signzy.com 2 2026-10-06 2026-10-06 ok
docs.signzy.com 12 2026-05-09 2026-09-05 ok
status.signzy.com 3 2026-06-13 2026-08-13 ok
encrypt.signzy.com 1 2026-06-18 2026-06-18 nodata
www.encrypt.signzy.com 1 2026-06-18 2026-06-18 nxdomain
www.signzy.com 6 2026-05-31 2026-09-30 ok

Programmatic access, with DNS A records: API GET /v1/hosts/signzy.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/signzy.com.