Note: Due to browser security restrictions, certificate checking by URL works only for the current domain. For other sites, please paste the certificate in PEM format.
🔐 About SSL/TLS Certificates
Subject: Who the certificate is issued to (domain name, organization)
Issuer: The Certificate Authority (CA) that issued the certificate
Validity Period: When the certificate starts and expires
Public Key: The cryptographic key used for encryption
Signature: Cryptographic signature proving the certificate is authentic
Extensions: Additional information like Subject Alternative Names (SANs)
💡 Common Uses
Verify certificate validity and expiration dates
Check Subject Alternative Names (SANs) for multi-domain certificates
Inspect certificate chain and issuer information
Troubleshoot SSL/TLS connection issues
Audit certificate configurations
⚠️ Privacy Note
All certificate decoding happens locally in your browser