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.

13 hosts · 321 ms

HostCertsFirst seenLast seenDNS
ubreakifix.com 3 2026-03-02 2026-08-03 ok
*.ubreakifix.com 2 2026-03-02 2026-08-03 —
*.stage.ubreakifix.com 1 2026-07-15 2026-07-15 —
store.ubreakifix.com 5 2026-05-11 2026-09-10 ok
www.store.ubreakifix.com 5 2026-05-11 2026-09-10 ok
franchising.ubreakifix.com 1 2025-09-14 2025-09-14 ok
www.franchising.ubreakifix.com 1 2025-09-14 2025-09-14 nxdomain
link.ubreakifix.com 6 2026-04-11 2026-10-05 ok
local.ubreakifix.com 3 2026-04-20 2026-08-20 ok
shop.ubreakifix.com 7 2026-04-20 2026-08-29 ok
website-partner-docs.ubreakifix.com 5 2026-05-25 2026-09-24 ok
stage-new.ubreakifix.com 2 2025-09-05 2026-08-06 ok
sre-stage-new.ubreakifix.com 3 2025-09-05 2026-08-06 ok

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