SSL Certificate Checker
Check SSL/TLS certificate validity, issuer, expiry date and certificate transparency logs for any domain. Free, instant, no signup.
🌐 Network & Web Tools
Free
Browser-based
What Does This Tool Check?
This tool queries crt.sh — a public certificate transparency log maintained by Sectigo. Certificate transparency logs record every SSL/TLS certificate issued by trusted CAs, making it possible to detect mis-issued certificates. Results show the most recently issued certificate for the domain.
SSL Certificate Components
| Field | Description |
|---|---|
| Common Name (CN) | Primary domain the certificate covers |
| Issuer | Certificate Authority that signed the certificate |
| Not Before | Certificate validity start date |
| Not After | Certificate expiry date |
| SANs | Additional domains covered by the certificate |
| Serial Number | Unique identifier assigned by the CA |
Certificate Transparency
Since 2018, all publicly trusted SSL certificates must be logged in Certificate Transparency (CT) logs. This allows anyone to monitor certificates issued for their domains. Tools like crt.sh and Google's CT report let you search the logs.