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.

7 hosts · 241 ms

HostCertsFirst seenLast seenDNS
trident.edu 6 2025-07-16 2026-07-16 ok
*.trident.edu 7 2025-07-16 2026-07-16 —
tlc.trident.edu 3 2025-07-25 2026-06-26 ok
stgportal.trident.edu 20 2026-02-11 2026-09-29 ok
mitel.trident.edu 3 2026-01-18 2026-02-17 nodata
www.mitel.trident.edu 3 2026-01-18 2026-02-17 nodata
enews.trident.edu 10 2026-04-23 2026-08-19 ok

Programmatic access, with DNS A records: API GET /v1/hosts/trident.edu (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/trident.edu.