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.

4 hosts · 249 ms

HostCertsFirst seenLast seenDNS
tulotero.co 3 2025-08-08 2026-07-20 ok
web.tulotero.co 3 2025-08-12 2026-07-20 ok
fp.web.tulotero.co 15 2025-10-29 2026-09-05 ok
www.tulotero.co 3 2025-08-08 2026-07-20 ok

Programmatic access, with DNS A records: API GET /v1/hosts/tulotero.co (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/tulotero.co.