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.

21 hosts · 341 ms

HostCertsFirst seenLast seenDNS
walrusfi.com 41 2026-05-10 2026-09-30 ok
*.walrusfi.com 36 2026-05-10 2026-09-30 —
api.qa.walrusfi.com 10 2026-05-08 2026-09-03 nxdomain
*.api.qa.walrusfi.com 10 2026-05-08 2026-09-03 —
fanout-prod.walrusfi.com 7 2026-06-22 2026-09-30 ok
api.demo.walrusfi.com 10 2026-05-08 2026-09-03 nxdomain
*.api.demo.walrusfi.com 10 2026-05-08 2026-09-03 —
api.app.walrusfi.com 10 2026-05-08 2026-09-03 ok
*.api.app.walrusfi.com 10 2026-05-08 2026-09-03 —
exp.walrusfi.com 1 2026-09-02 2026-09-02 ok
status.walrusfi.com 1 2026-10-06 2026-10-06 ok
fanout-test.walrusfi.com 7 2026-06-22 2026-09-30 ok
api.test.walrusfi.com 10 2026-05-08 2026-09-03 ok
*.api.test.walrusfi.com 10 2026-05-08 2026-09-03 —
api.dev.walrusfi.com 10 2026-05-08 2026-09-03 ok
*.api.dev.walrusfi.com 10 2026-05-08 2026-09-03 —
www.walrusfi.com 7 2026-05-02 2026-09-05 ok
fanout-sandbox.walrusfi.com 7 2026-06-22 2026-09-30 ok
api.sandbox.walrusfi.com 10 2026-05-08 2026-09-03 ok
*.api.sandbox.walrusfi.com 10 2026-05-08 2026-09-03 —
security.walrusfi.com 8 2026-05-01 2026-08-27 ok

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