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 · 379 ms

HostCertsFirst seenLast seenDNS
a1.rs 1 2026-02-12 2026-02-12 ok
*.a1.rs 1 2026-02-12 2026-02-12 —
mail02.a1.rs 1 2025-11-28 2025-11-28 ok
*.data.a1.rs 1 2026-06-15 2026-06-15 —
zabava.a1.rs 11 2025-10-27 2026-08-24 ok
wonderfulai-prod.a1.rs 1 2026-07-22 2026-07-22 ok
app.wonderfulai-prod.a1.rs 1 2026-07-22 2026-07-22 ok
wonderful.app.wonderfulai-prod.a1.rs 1 2026-07-22 2026-07-22 ok
chat.wonderfulai-prod.a1.rs 1 2026-07-22 2026-07-22 ok
cloud.a1.rs 1 2025-10-03 2025-10-03 ok
login.cloud.a1.rs 1 2025-10-03 2025-10-03 ok
znanje.a1.rs 1 2026-09-24 2026-09-24 ok
gate.a1.rs 1 2026-02-12 2026-02-12 ok
mail.a1.rs 2 2025-06-23 2026-06-23 ok
cloud.email.a1.rs 1 2026-02-03 2026-02-03 ok
image.email.a1.rs 5 2026-04-09 2026-09-21 ok
click.email.a1.rs 1 2026-02-03 2026-02-03 ok
view.email.a1.rs 1 2026-02-03 2026-02-03 ok
autodiscover.a1.rs 2 2025-06-23 2026-06-23 ok
doh.netprotectplus.a1.rs 2 2026-07-10 2026-07-13 ok
www.doh.netprotectplus.a1.rs 2 2026-07-10 2026-07-13 nxdomain
sst.a1.rs 3 2026-05-05 2026-08-22 ok
wonderfulai-dev.a1.rs 1 2026-07-22 2026-07-22 ok
app.wonderfulai-dev.a1.rs 1 2026-07-22 2026-07-22 ok
wonderful.app.wonderfulai-dev.a1.rs 1 2026-07-22 2026-07-22 ok
chat.wonderfulai-dev.a1.rs 1 2026-07-22 2026-07-22 ok
*.fix.a1.rs 1 2026-06-09 2026-06-09 —

Programmatic access, with DNS A records: API GET /v1/hosts/a1.rs (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/a1.rs.