About Certificate Decoder
Decode and analyze PEM-encoded X.509 SSL/TLS certificates instantly. View subject and issuer details, validity period, certificate extensions, public key information, and cryptographic fingerprints. Essential for web administrators and security professionals verifying certificate configurations.
How to Use
- 1Paste your PEM-encoded certificate into the input area
- 2Click "Decode Certificate" to parse
- 3Review certificate details including subject, issuer, and validity
- 4Check extensions like Subject Alternative Names
- 5Copy fingerprints for verification
Key Features
- Full X.509 certificate parsing
- Subject and issuer details
- Validity period with expiry warnings
- Public key algorithm and size
- Certificate extensions (SAN, Key Usage, etc.)
- SHA-1 and SHA-256 fingerprints
- Signature algorithm identification
- Version and serial number display
Common Use Cases
Frequently Asked Questions
What is a PEM certificate?
PEM (Privacy Enhanced Mail) is a Base64-encoded format for certificates, bounded by -----BEGIN CERTIFICATE----- and -----END CERTIFICATE----- markers.
How do I get a certificate to decode?
Export from your browser by clicking the lock icon, download from your server, or use openssl commands like "openssl s_client -connect domain.com:443".
Privacy First
All processing happens directly in your browser. Your files never leave your device and are never uploaded to any server.
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