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.

15 hosts · 257 ms

HostCertsFirst seenLast seenDNS
smarthr.co.jp 35 2025-10-07 2026-10-06 ok
*.smarthr.co.jp 21 2026-04-12 2026-10-06 —
jinrouda.smarthr.co.jp 5 2026-05-26 2026-09-23 ok
site.smarthr.co.jp 10 2026-05-07 2026-09-02 ok
well-working.smarthr.co.jp 2 2026-04-11 2026-09-11 ok
rubykaigi.smarthr.co.jp 4 2026-04-24 2026-10-05 ok
real.smarthr.co.jp 3 2026-04-30 2026-08-16 ok
shaho.smarthr.co.jp 4 2026-04-11 2026-09-16 ok
gifts-for-social-goods.smarthr.co.jp 6 2026-04-27 2026-10-01 ok
workandfes.smarthr.co.jp 2 2026-04-08 2026-09-08 ok
stg-workandfes.smarthr.co.jp 2 2026-04-08 2026-09-08 ok
pages.smarthr.co.jp 18 2026-05-28 2026-09-28 ok
recruit.smarthr.co.jp 12 2026-05-27 2026-09-29 ok
*.recruit.smarthr.co.jp 4 2026-09-29 2026-09-29 —
accessibility.smarthr.co.jp 5 2026-04-24 2026-08-23 ok

Programmatic access, with DNS A records: API GET /v1/hosts/smarthr.co.jp (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/smarthr.co.jp.