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 · 341 ms

HostCertsFirst seenLast seenDNS
sidedeal.com 2 2026-03-09 2026-07-02 ok
trk2.sidedeal.com 13 2026-04-10 2026-10-04 ok
static.sidedeal.com 1 2026-07-02 2026-07-02 ok
trk.sidedeal.com 2 2025-08-15 2026-07-15 ok
trk.mail.sidedeal.com 15 2026-04-09 2026-10-03 ok
shop.sidedeal.com 10 2026-04-21 2026-09-19 ok
tagmanager.sidedeal.com 4 2026-04-27 2026-09-10 ok
www.sidedeal.com 2 2026-03-09 2026-07-02 ok

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