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 · 293 ms

HostCertsFirst seenLast seenDNS
transitic.com 23 2026-04-10 2026-08-24 ok
*.transitic.com 23 2026-04-10 2026-08-24 —
*.pages.transitic.com 23 2026-04-10 2026-08-24 —
mta-sts.transitic.com 1 2026-08-25 2026-08-25 ok
*.git.transitic.com 23 2026-04-10 2026-08-24 —

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