Certificate Transparency

Publicly logged TLS certificates for a domain from CT logs

Free Online Tool

Certificate Transparency — Complete Guide & Instructions

Query public Certificate Transparency logs for every certificate ever issued to a domain — including subdomains — with the issuing CA and validity window for each. Useful for subdomain discovery and spotting rogue certificates.

How to Use Certificate Transparency

  1. 1 Enter a domain name.
  2. 2 Click Check — CT logs are searched via crt.sh.
  3. 3 Browse issuers and the recent certificate table.

Key Features & Capabilities

  • Wildcard query covers all logged subdomains.
  • Issuer summary across the history.
  • Recent certificates table with validity windows.