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 · 234 ms

HostCertsFirst seenLast seenDNS
cside.dev 40 2026-04-19 2026-10-02 ok
*.cside.dev 24 2026-04-19 2026-09-10 —
vmc.cside.dev 8 2026-05-22 2026-09-17 ok
dashboard.cside.dev 9 2026-06-06 2026-10-02 nxdomain
tracking.cside.dev 5 2026-05-30 2026-09-26 ok
prehog.cside.dev 2 2025-09-01 2025-09-01 nodata
merch.cside.dev 15 2026-04-14 2026-09-27 ok
lp.cside.dev 6 2026-04-25 2026-08-23 ok
tools.cside.dev 7 2026-05-07 2026-09-02 ok
proxy.cside.dev 2 2026-02-12 2026-02-12 nodata

Programmatic access, with DNS A records: API GET /v1/hosts/cside.dev (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/cside.dev.