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.

12 hosts · 267 ms

HostCertsFirst seenLast seenDNS
featured.com 5 2026-04-24 2026-08-28 ok
eve.featured.com 1 2026-08-14 2026-08-14 ok
blog.featured.com 19 2026-04-25 2026-09-01 ok
www.blog.featured.com 14 2026-05-06 2026-09-01 ok
internal.featured.com 5 2026-06-03 2026-10-04 ok
mcp.featured.com 5 2026-04-22 2026-08-28 ok
docs.featured.com 8 2026-06-02 2026-06-02 ok
status.featured.com 5 2026-04-26 2026-08-28 ok
news.featured.com 1 2026-09-14 2026-09-14 ok
chat.featured.com 5 2026-05-28 2026-09-30 ok
www.featured.com 5 2026-04-23 2026-08-24 ok
factory.featured.com 3 2026-07-21 2026-09-23 ok

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