crt.sh - Certificate Search
CT log viewer aggregating certificate data from multiple Certificate Transparency logs. Search for all certificates ever issued to a domain to…
Platforms: Web · Last verified September 7, 2026
CT log viewer aggregating certificate data from multiple Certificate Transparency logs. Search for all certificates ever issued to a domain to discover subdomains and detect certificate misuse.
Only use this tool against systems you own or are explicitly authorized to test — see the disclaimer.
Getting started
Best for: Certificate search, subdomain discovery via CT logs, detecting unauthorized certificates. See the official site linked above for details.