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 · 285 ms

HostCertsFirst seenLast seenDNS
bitcoin.com.au 25 2026-04-15 2026-09-15 ok
*.bitcoin.com.au 27 2026-04-14 2026-09-15 —
link.bitcoin.com.au 20 2026-05-05 2026-08-31 ok
*.email.bitcoin.com.au 9 2026-05-06 2026-09-01 —
metrics.bitcoin.com.au 8 2026-05-01 2026-08-27 ok

Programmatic access, with DNS A records: API GET /v1/hosts/bitcoin.com.au (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/bitcoin.com.au.