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.

27 hosts · 455 ms

HostCertsFirst seenLast seenDNS
viktor.com 17 2026-05-13 2026-09-14 ok
*.viktor.com 12 2026-05-13 2026-09-14 —
hub.viktor.com 4 2026-08-03 2026-10-01 ok
ref.viktor.com 5 2026-05-14 2026-09-16 ok
dogfooding.viktor.com 2 2026-09-09 2026-09-09 ok
staging.viktor.com 5 2026-05-13 2026-09-13 ok
phi.viktor.com 3 2026-07-03 2026-09-03 ok
api.viktor.com 6 2026-05-20 2026-09-16 ok
staging-api.viktor.com 5 2026-05-25 2026-09-22 ok
phi-api.viktor.com 3 2026-07-08 2026-09-05 ok
ws-api.viktor.com 5 2026-07-21 2026-09-25 ok
staging-ws-api.viktor.com 5 2026-07-21 2026-09-24 ok
email.mail.viktor.com 2 2026-06-30 2026-08-25 ok
lgtm.viktor.com 2 2026-09-29 2026-09-29 ok
app.viktor.com 5 2026-05-13 2026-09-14 ok
docs.viktor.com 2 2026-08-12 2026-08-12 ok
friends.viktor.com 2 2026-09-23 2026-09-23 ok
files.viktor.com 5 2026-06-26 2026-07-02 nxdomain
vis.viktor.com 2 2026-09-10 2026-09-10 ok
forms.viktor.com 4 2026-06-19 2026-09-16 ok
productos.viktor.com 2 2026-08-20 2026-08-20 ok
assets.viktor.com 5 2026-08-06 2026-10-04 ok
status.viktor.com 2 2026-07-31 2026-07-31 ok
v.viktor.com 6 2026-06-10 2026-08-10 ok
sandbox.v.viktor.com 6 2026-06-10 2026-08-10 ok
www.viktor.com 5 2026-05-13 2026-09-14 ok
pay.viktor.com 6 2026-06-13 2026-08-11 ok

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