Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts, first/last seen and live DNS status.

3 hosts · 216 ms

HostCertsFirst seenLast seenDNS
picnic.nl 3 2025-11-08 2026-05-15 ok
*.picnic.nl 3 2025-11-08 2026-05-15 —
click.picnic.nl 2 2025-09-08 2026-08-09 ok

Programmatic access, with DNS A records: API GET /v1/hosts/picnic.nl (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/picnic.nl.