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.

6 hosts · 218 ms

HostCertsFirst seenLast seenDNS
stairwayinvest.com 4 2026-04-20 2026-09-08 ok
demo.stairwayinvest.com 3 2026-05-27 2026-09-11 ok
mta-sts.stairwayinvest.com 5 2026-05-10 2026-09-02 ok
au.stairwayinvest.com 4 2026-04-14 2026-09-22 ok
www.au.stairwayinvest.com 5 2026-04-13 2026-09-27 ok
www.stairwayinvest.com 4 2026-04-20 2026-09-08 ok

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