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 · 264 ms

HostCertsFirst seenLast seen
schaeffer.com 3 2026-01-08 2026-04-07
*.schaeffer.com 3 2026-01-08 2026-04-07
sir-mail6.schaeffer.com 1 2025-11-18 2025-11-18
www.sir-mail6.schaeffer.com 1 2025-11-18 2025-11-18
mail.schaeffer.com 4 2025-08-22 2026-08-24
www.mail.schaeffer.com 4 2025-08-22 2026-08-24
awsvpn.schaeffer.com 2 2025-10-02 2026-09-01
lyris.schaeffer.com 3 2026-03-17 2026-08-31
www.lyris.schaeffer.com 3 2026-03-17 2026-08-31

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