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.

20 hosts · 353 ms

HostCertsFirst seenLast seenDNS
hrgo.co.uk 1 2026-05-18 2026-05-18 ok
*.hrgo.co.uk 1 2026-05-18 2026-05-18 —
betta.hrgo.co.uk 8 2026-05-02 2026-08-28 ok
font-mcp-auth-spike.hrgo.co.uk 1 2026-07-17 2026-07-17 ok
azure.hrgo.co.uk 4 2026-04-18 2026-08-10 ok
labs.staging.hrgo.co.uk 5 2026-05-16 2026-09-13 ok
consultants.staging.hrgo.co.uk 5 2026-05-16 2026-09-13 ok
font.staging.hrgo.co.uk 5 2026-05-17 2026-09-14 ok
poland-stage-pl.hrgo.co.uk 2 2026-02-14 2026-06-06 ok
azurevpn.hrgo.co.uk 1 2026-05-26 2026-05-26 ok
www.azurevpn.hrgo.co.uk 1 2026-05-26 2026-05-26 nxdomain
bad-unicorn.hrgo.co.uk 1 2026-05-28 2026-05-28 ok
labs.demo.hrgo.co.uk 5 2026-05-16 2026-09-13 ok
consultants.demo.hrgo.co.uk 5 2026-05-16 2026-09-13 ok
font.demo.hrgo.co.uk 5 2026-05-17 2026-09-14 ok
font-mcp.hrgo.co.uk 1 2026-07-18 2026-07-18 ok
lms.hrgo.co.uk 3 2026-05-21 2026-08-13 ok
mta-sts.hrgo.co.uk 4 2025-11-11 2026-09-12 ok
font.hrgo.co.uk 5 2026-05-21 2026-09-18 ok
www.hrgo.co.uk 8 2026-05-02 2026-08-29 ok

Programmatic access, with DNS A records: API GET /v1/hosts/hrgo.co.uk (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/hrgo.co.uk.