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.

14 hosts · 292 ms

HostCertsFirst seenLast seenDNS
halocollar.com 24 2025-07-27 2026-09-30 ok
*.halocollar.com 24 2025-07-27 2026-09-30 —
returnstaging.halocollar.com 13 2026-06-02 2026-09-28 ok
billing.halocollar.com 4 2026-05-13 2026-07-12 ok
i.halocollar.com 3 2026-05-17 2026-09-04 ok
pmportal.halocollar.com 1 2026-09-17 2026-09-17 ok
go.halocollar.com 12 2026-05-09 2026-09-04 ok
server.halocollar.com 4 2026-06-02 2026-09-16 ok
clicks.halocollar.com 4 2025-09-17 2026-09-17 ok
www.clicks.halocollar.com 4 2025-09-17 2026-09-17 nxdomain
returns.halocollar.com 9 2026-06-02 2026-09-28 ok
halo-api.agents.halocollar.com 4 2026-04-24 2026-06-23 ok
halo.agents.halocollar.com 2 2026-06-06 2026-06-06 ok
support.halocollar.com 5 2026-05-27 2026-09-24 ok

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