SSL Certificate Decoder

Decode and analyze SSL/TLS certificates. Upload a certificate file or paste certificate data to view detailed information.

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Certificate Decoding & Analysis

Upload or paste any SSL/TLS certificate to extract detailed information, validate structure, and analyze security properties.

Certificate Details

Extract subject, issuer, serial numbers, validity periods, and all certificate metadata in human-readable format.

Public Key Analysis

Analyze public key algorithms, key sizes, RSA modulus and exponent values for comprehensive cryptographic assessment.

Extensions & Usage

Parse certificate extensions including Subject Alternative Names, Key Usage, and Extended Key Usage policies.

Fingerprints & Hashes

Generate SHA-1, SHA-256, and MD5 fingerprints for certificate identification and integrity verification.

Authority Information

Extract OCSP responder URLs, CRL distribution points, and CA issuer information for validation.

Validity Analysis

Check certificate validity periods, expiration status, and identify self-signed certificates automatically.

What Gets Decoded

Our comprehensive decoder extracts every detail from your certificate for complete analysis.

Certificate Structure

Version, serial number, signature algorithm
Subject and issuer distinguished names
Validity period and expiration analysis
Public key details and cryptographic parameters
Certificate fingerprints (SHA-1, SHA-256, MD5)

Extensions & Advanced Features

Subject Alternative Names (SAN)
Key Usage and Extended Key Usage
Authority and Subject Key Identifiers
CRL distribution points and OCSP URLs
Certificate type identification
📋 Multiple Input Methods

Upload certificate files (.pem, .crt, .cer) or paste certificate data directly. Works with any X.509 certificate in PEM format.

Supported Certificate Types

Decode any X.509 certificate regardless of its intended use case.

SSL/TLS Server

Website certificates for HTTPS connections and web server authentication.

Code Signing

Certificates used to sign software applications and verify publisher identity.

S/MIME Email

Email encryption and digital signature certificates for secure communications.

Client Authentication

Client certificates for mutual TLS authentication and user identification.