SSL Certificate Decoder

What is SSL Certificate Decoder?

Paste a PEM-encoded certificate to decode and inspect its details. View subject, issuer, validity period, key usage, Subject Alternative Names (SANs), and certificate chain information.

Features & Benefits

• Decode PEM certificates
• View expiration dates
• Inspect certificate chain
• Check SANs (domains)
• Key usage analysis
• Certificate validation

Frequently Asked Questions

What is a PEM certificate?

PEM (Privacy Enhanced Mail) is a base64-encoded format starting with '-----BEGIN CERTIFICATE-----'. It's the most common certificate format.

What are Subject Alternative Names (SANs)?

SANs list all domain names a certificate is valid for. Modern certificates rely on SANs rather than the Common Name (CN) field.

How do I check certificate expiration?

Paste your certificate here to see the 'Not After' date, or use: openssl x509 -enddate -noout -in cert.pem

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How-To Guides