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.

15 hosts · 306 ms

HostCertsFirst seenLast seenDNS
robertwalters.com 3 2025-09-01 2026-08-19 ok
*.robertwalters.com 1 2026-04-10 2026-04-10 —
connect1.robertwalters.com 10 2026-06-02 2026-09-29 ok
aiplayground.robertwalters.com 2 2026-02-23 2026-07-13 ok
engage.robertwalters.com 9 2026-05-29 2026-10-02 ok
online.robertwalters.com 1 2026-01-01 2026-01-01 ok
smartscope.robertwalters.com 2 2025-09-17 2026-08-18 ok
wifi.robertwalters.com 1 2026-05-08 2026-05-08 nxdomain
info.robertwalters.com 10 2026-05-08 2026-09-04 ok
go.robertwalters.com 10 2026-04-20 2026-08-17 ok
ai-ads.robertwalters.com 2 2026-02-13 2026-07-06 ok
events.robertwalters.com 2 2025-06-18 2026-05-17 ok
connect.robertwalters.com 8 2026-05-07 2026-09-02 ok
www.robertwalters.com 2 2025-09-01 2026-08-19 ok
ipay.robertwalters.com 2 2025-06-12 2026-06-19 ok

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