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.

4 hosts · 152 ms

HostCertsFirst seenLast seen
mio.se 16 2025-11-25 2026-09-15
*.mio.se 16 2025-11-25 2026-09-15
www.soffbyggare.mio.se 2 2026-03-01 2026-06-24
medl.mio.se 5 2026-04-24 2026-08-22

Programmatic access: API GET /v1/hosts/mio.se (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/mio.se.