Certificate & CSR Decoder

Decode X.509 certificates and Certificate Signing Requests (CSRs) entirely in your browser. Your sensitive data never leaves your device.

Input Certificate, CSR, or Private Key

Upload a file or paste your PEM-encoded certificate, CSR, or private key below.

Supports: .pem, .cer, .crt, .csr, .der, .key, .pfx, .p12 (max 5MB)

Decoded certificate or CSR details will appear here

Certificate Tools