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 · 322 ms

HostCertsFirst seenLast seen
u-friends.com 4 2025-09-23 2026-10-14
*.u-friends.com 1 2025-12-17 2025-12-17
dev-api.u-friends.com 1 2025-11-03 2025-11-03
dev-admin.u-friends.com 1 2025-11-03 2025-11-03
dev.u-friends.com 1 2025-11-03 2025-11-03
www.u-friends.com 3 2025-09-23 2026-10-14

Programmatic access: API GET /v1/hosts/u-friends.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/u-friends.com.