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.

6 hosts · 236 ms

HostCertsFirst seenLast seen
zerorez.com 11 2026-04-20 2026-10-04
*.zerorez.com 11 2026-04-20 2026-10-04
portal.zerorez.com 1 2026-01-30 2026-01-30
www.portal.zerorez.com 1 2026-01-30 2026-01-30
mail.zerorez.com 5 2026-05-27 2026-09-24
try.zerorez.com 12 2026-06-13 2026-10-09

Programmatic access: API GET /v1/hosts/zerorez.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/zerorez.com.