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.

9 hosts · 303 ms

HostCertsFirst seenLast seen
yousician.com 9 2025-08-02 2026-10-03
*.yousician.com 9 2025-08-02 2026-10-03
unmuted.yousician.com 2 2025-06-20 2026-05-20
*.unmuted.yousician.com 2 2025-06-20 2026-05-20
*.e.yousician.com 4 2025-09-15 2026-08-17
design.yousician.com 3 2026-06-11 2026-08-10
jenkins.yousician.com 5 2026-05-27 2026-09-24
lessons.yousician.com 5 2026-05-09 2026-09-09
support.yousician.com 4 2026-04-17 2026-08-15

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