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.

3 hosts · 323 ms

HostCertsFirst seenLast seenDNS
handycomic.jp 2 2025-08-28 2026-07-29 ok
sp.handycomic.jp 3 2025-10-22 2026-09-22 ok
bsreader.handycomic.jp 2 2026-02-08 2026-02-11 ok

Programmatic access, with DNS A records: API GET /v1/hosts/handycomic.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/handycomic.jp.