About

CT Monitoring provides an independent, readable view of the public Certificate Transparency ecosystem.

What we do

Our collectors follow public CT logs, verify their entries and produce aggregate measurements of the certificates and domain names observed. The public site receives summary snapshots every 15 minutes; it never receives the collectors' internal sketches or private monitoring watchlists.

Why it matters

TLS certificates are foundational to the web. Public logging makes issuance auditable, helps surface mistakes and supports monitoring for unauthorised certificates. Aggregate statistics also reveal the extraordinary scale and rate of change of the ecosystem.

Related monitoring

The collectors also support DNSVerify's opt-in certificate monitoring. Customer-specific results remain within that service and are not exposed by this statistics site.