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.

7 hosts · 326 ms

HostCertsFirst seenLast seenDNS
outcast-clothing.com 19 2026-05-15 2026-09-24 ok
okta.outcast-clothing.com 8 2026-05-04 2026-09-05 ok
test.trk.outcast-clothing.com 2 2026-08-13 2026-08-13 ok
app.outcast-clothing.com 15 2026-04-27 2026-09-12 ok
mta-sts.outcast-clothing.com 3 2026-05-09 2026-08-03 ok
www.outcast-clothing.com 15 2026-05-15 2026-09-25 ok
survey.outcast-clothing.com 1 2026-02-11 2026-02-11 ok

Programmatic access, with DNS A records: API GET /v1/hosts/outcast-clothing.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/outcast-clothing.com.