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.

29 hosts · 320 ms

HostCertsFirst seenLast seenDNS
flo.health 122 2026-04-10 2026-10-04 ok
*.flo.health 29 2026-04-25 2026-09-02 —
med.flo.health 8 2026-04-22 2026-08-19 ok
staging.flo.health 31 2026-05-04 2026-09-17 ok
*.staging.flo.health 18 2026-05-18 2026-09-17 —
auth.staging.flo.health 34 2026-05-04 2026-10-01 ok
*.auth.staging.flo.health 8 2026-09-10 2026-10-01 —
vercel.staging.flo.health 4 2026-04-12 2026-08-16 ok
*.vercel.staging.flo.health 8 2026-04-09 2026-08-16 —
app.staging.flo.health 4 2026-04-17 2026-08-16 ok
auth-dev.staging.flo.health 26 2026-05-27 2026-09-28 ok
mcp-gw.staging.flo.health 4 2026-05-13 2026-07-11 nxdomain
applewatch.flo.health 5 2026-05-19 2026-09-21 ok
auth.flo.health 31 2026-05-25 2026-09-25 ok
*.auth.flo.health 4 2026-09-23 2026-09-25 —
plan.flo.health 5 2026-04-28 2026-08-31 ok
promo.flo.health 5 2026-04-22 2026-08-25 ok
intro.flo.health 5 2026-04-30 2026-09-04 ok
help.flo.health 7 2026-05-28 2026-09-25 ok
app.flo.health 5 2026-05-12 2026-09-13 ok
rf.worker.js.staging.app.flo.health 14 2026-04-22 2026-08-18 ok
rf.worker.js.production.app.flo.health 16 2026-04-21 2026-08-17 ok
echo-worker.app.flo.health 24 2026-04-12 2026-09-15 ok
get-relevant-features.app.flo.health 12 2026-04-10 2026-10-04 ok
rf.worker.rust.app.flo.health 14 2026-04-15 2026-08-11 ok
tms.flo.health 3 2026-05-06 2026-08-24 ok
bundled.scalajs.workers.flo.health 13 2026-06-06 2026-10-03 nxdomain
mta-sts.flo.health 1 2026-08-07 2026-08-07 ok
quiz.flo.health 5 2026-04-23 2026-08-25 ok

Programmatic access, with DNS A records: API GET /v1/hosts/flo.health (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/flo.health.