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 · 305 ms

HostCertsFirst seenLast seenDNS
offdeal.io 30 2026-04-10 2026-09-19 ok
*.offdeal.io 19 2026-04-19 2026-09-19 —
posthog.offdeal.io 11 2026-04-10 2026-08-06 nxdomain
dev-uploads.offdeal.io 3 2026-05-09 2026-08-27 ok
t.offdeal.io 4 2026-04-15 2026-08-13 ok

Programmatic access, with DNS A records: API GET /v1/hosts/offdeal.io (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/offdeal.io.