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.

5 hosts · 292 ms

HostCertsFirst seenLast seenDNS
whitecoatwaste.org 3 2026-04-19 2026-08-21 ok
blog.whitecoatwaste.org 3 2026-04-19 2026-08-21 ok
action.whitecoatwaste.org 8 2026-05-03 2026-09-13 ok
act.whitecoatwaste.org 10 2026-04-22 2026-08-18 ok
www.whitecoatwaste.org 3 2026-04-19 2026-08-21 ok

Programmatic access, with DNS A records: API GET /v1/hosts/whitecoatwaste.org (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/whitecoatwaste.org.