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.

4 hosts · 224 ms

HostCertsFirst seenLast seenDNS
cloud.mailings.linklaters.com 2 2026-04-19 2026-09-20 ok
image.mailings.linklaters.com 3 2026-02-04 2026-05-27 ok
click.mailings.linklaters.com 3 2026-04-18 2026-09-19 ok
view.mailings.linklaters.com 3 2026-04-18 2026-09-19 ok

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