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 · 321 ms

HostCertsFirst seenLast seenDNS
muddymats.com 11 2026-05-20 2026-09-29 ok
page.muddymats.com 1 2026-09-30 2026-09-30 nodata
preprod.page.muddymats.com 1 2026-09-30 2026-09-30 nxdomain
blog.muddymats.com 8 2026-06-13 2026-09-30 ok
preprod.blog.muddymats.com 1 2026-09-30 2026-09-30 ok
i.muddymats.com 6 2026-04-19 2026-09-24 ok
knnfl.muddymats.com 10 2026-04-24 2026-08-20 ok
trk.email.muddymats.com 8 2026-04-24 2026-08-20 ok
shop.muddymats.com 1 2026-01-19 2026-01-19 ok
buys.muddymats.com 5 2026-05-07 2026-09-06 ok
account.muddymats.com 9 2026-04-26 2026-09-03 ok
www.muddymats.com 16 2026-05-21 2026-10-01 ok
buy.muddymats.com 6 2026-04-16 2026-10-01 ok
www.buy.muddymats.com 2 2026-04-16 2026-10-01 nxdomain

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