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.

8 hosts · 316 ms

HostCertsFirst seenLast seenDNS
solo.to 23 2026-06-04 2026-10-01 ok
*.solo.to 23 2026-06-04 2026-10-01 —
a.solo.to 8 2026-05-08 2026-09-18 ok
b.solo.to 5 2026-06-06 2026-09-06 ok
blog.solo.to 10 2026-05-11 2026-09-06 ok
email.solo.to 5 2026-05-23 2026-09-20 ok
help.solo.to 5 2026-05-05 2026-09-02 ok
email.at.solo.to 5 2026-05-23 2026-09-20 ok

Programmatic access, with DNS A records: API GET /v1/hosts/solo.to (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/solo.to.