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.

19 hosts · 280 ms

HostCertsFirst seenLast seenDNS
gmo-rast.co.jp 7 2026-01-08 2026-08-13 ok
*.gmo-rast.co.jp 6 2026-01-08 2026-08-13 —
redmine.gmo-rast.co.jp 4 2026-04-19 2026-08-15 ok
rstudio-stg.gmo-rast.co.jp 2 2026-03-09 2026-08-09 ok
*.rstudio-stg.gmo-rast.co.jp 6 2026-03-09 2026-08-10 —
wiki.iwaki.gmo-rast.co.jp 3 2026-06-19 2026-08-18 ok
wiki.gmo-rast.co.jp 4 2026-04-15 2026-08-17 ok
rstudio.gmo-rast.co.jp 1 2026-01-06 2026-01-06 ok
*.rstudio.gmo-rast.co.jp 5 2026-03-10 2026-08-10 —
wikijs.gmo-rast.co.jp 3 2026-06-19 2026-08-18 ok
report.gmo-rast.co.jp 7 2026-07-29 2026-09-26 ok
forum-spike.tohoku.gmo-rast.co.jp 14 2026-05-09 2026-09-10 ok
forum-stg.tohoku.gmo-rast.co.jp 8 2026-05-26 2026-07-26 ok
forum.tohoku.gmo-rast.co.jp 14 2026-05-15 2026-09-24 ok
forum-dev.tohoku.gmo-rast.co.jp 12 2026-05-20 2026-07-19 ok
rstudio-dev.gmo-rast.co.jp 2 2026-03-07 2026-08-07 ok
*.rstudio-dev.gmo-rast.co.jp 6 2026-03-07 2026-08-07 —
survey.gmo-rast.co.jp 1 2026-09-15 2026-09-15 ok
twenty.gmo-rast.co.jp 5 2026-04-26 2026-08-25 ok

Programmatic access, with DNS A records: API GET /v1/hosts/gmo-rast.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/gmo-rast.co.jp.