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.

10 hosts · 301 ms

HostCertsFirst seenLast seenDNS
papier.com 4 2025-12-01 2026-09-12 ok
*.papier.com 3 2026-04-12 2026-09-12 —
tag.papier.com 1 2025-12-14 2025-12-14 ok
search.papier.com 2 2026-04-12 2026-09-12 ok
companion.papier.com 1 2026-06-11 2026-06-11 ok
clicks.papier.com 1 2025-11-16 2025-11-16 ok
ss.papier.com 2 2026-05-07 2026-05-07 ok
rkt.papier.com 5 2026-04-28 2026-09-15 ok
www.papier.com 5 2026-04-12 2026-09-12 ok
thelibrary.papier.com 1 2025-07-18 2025-07-18 nxdomain

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