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.

12 hosts · 256 ms

HostCertsFirst seenLast seenDNS
ad-astra.fr 7 2026-04-13 2026-08-12 ok
*.ad-astra.fr 1 2026-06-01 2026-06-01 —
mail.ad-astra.fr 9 2026-05-03 2026-10-02 ok
eye.mail.ad-astra.fr 9 2026-05-03 2026-10-02 ok
img.mail.ad-astra.fr 9 2026-05-03 2026-10-02 ok
landings.mail.ad-astra.fr 9 2026-05-03 2026-10-02 ok
forms.mail.ad-astra.fr 9 2026-05-03 2026-10-02 ok
enterpriseregistration.ad-astra.fr 2 2025-11-19 2026-06-08 ok
amundi-alto.ad-astra.fr 1 2025-10-08 2025-10-08 ok
mta-sts.ad-astra.fr 5 2026-05-23 2026-09-20 ok
projet.ad-astra.fr 4 2026-04-13 2026-08-11 ok
www.ad-astra.fr 4 2026-04-13 2026-08-12 ok

Programmatic access, with DNS A records: API GET /v1/hosts/ad-astra.fr (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/ad-astra.fr.