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 · 276 ms

HostCertsFirst seenLast seenDNS
outblaze.com 7 2026-03-09 2026-09-06 ok
*.outblaze.com 6 2025-09-28 2026-08-28 —
blog.outblaze.com 8 2026-04-22 2026-08-18 ok
www.outblaze.com 4 2026-04-20 2026-09-06 ok

Programmatic access, with DNS A records: API GET /v1/hosts/outblaze.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/outblaze.com.