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.

11 hosts · 283 ms

HostCertsFirst seenLast seenDNS
fast2sms.com 17 2026-04-30 2026-09-25 ok
*.fast2sms.com 12 2026-04-30 2026-09-15 —
s3.fast2sms.com 6 2026-06-29 2026-08-27 ok
mail.fast2sms.com 5 2026-05-26 2026-09-25 ok
automation.fast2sms.com 3 2026-07-07 2026-09-06 ok
integration.fast2sms.com 5 2026-04-14 2026-10-02 ok
reseller.fast2sms.com 5 2026-05-11 2026-09-10 ok
docs.fast2sms.com 5 2026-05-07 2026-09-06 ok
files.fast2sms.com 9 2026-04-13 2026-09-10 ok
www.fast2sms.com 5 2026-05-26 2026-09-25 ok
shopify.fast2sms.com 2 2026-07-07 2026-07-07 nxdomain

Programmatic access, with DNS A records: API GET /v1/hosts/fast2sms.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/fast2sms.com.