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.

14 hosts · 284 ms

HostCertsFirst seenLast seenDNS
mysa.io 28 2025-10-30 2026-10-03 ok
*.mysa.io 4 2026-01-06 2026-09-27 —
int-yes1.mysa.io 1 2025-10-06 2025-10-06 ok
www.int-yes1.mysa.io 1 2025-10-06 2025-10-06 ok
int-axis1.mysa.io 1 2026-06-10 2026-06-10 nodata
www.int-axis1.mysa.io 1 2026-06-10 2026-06-10 nxdomain
payable.mysa.io 6 2026-04-13 2026-09-07 ok
onboarding.mysa.io 4 2026-05-25 2026-07-21 ok
www.onboarding.mysa.io 4 2026-05-25 2026-07-21 nxdomain
prod-vpn.mysa.io 4 2026-04-17 2026-09-26 ok
retool-prod-vpn.mysa.io 3 2026-06-26 2026-09-15 ok
support.mysa.io 5 2026-05-21 2026-09-18 ok
trust.mysa.io 5 2026-05-03 2026-09-01 ok
www.mysa.io 30 2025-10-30 2026-10-03 ok

Programmatic access, with DNS A records: API GET /v1/hosts/mysa.io (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/mysa.io.