KC Tools

SSL / X.509 Certificate & CSR Decoder

Inspect and parse X.509 SSL/TLS Certificates and Certificate Signing Requests (CSR). Examine Subject & Issuer fields, SANs, validity dates, RSA/ECDSA key information, and cryptographic fingerprints.

Presets:

Sample X.509 Certificate

Sample CSR (Request)

Certificate Parse Error: Too few bytes to read ASN.1 value.

PEM Input

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Certificate Details

Paste an X.509 Certificate or CSR on the left to decode.