Cert Decoder

• Instant PEM decoding: Decodes PEM certificates instantly and displays essential certificate details, including:
• Issuer
• Validity period (start and expiry dates)
• Subject Alternative Names (SAN)
• Serial number
• Fingerprint (SHA1, SHA256, or MD5)
• Privacy-first: All processing happens entirely in your browser, ensuring no certificate data is ever leaked.
• Retro and minimalist: It's pure HTML—something you rarely see these days, offering a nostalgic, minimalist look.

For Developers and System Administrators

• Certificate Validation: Quickly verify the contents of SSL/TLS certificates, including issuer, validity period, and Subject Alternative Names (SAN), to ensure they are correct before deployment
• Troubleshooting SSL Issues: Decode certificates to identify potential issues, such as mismatched SANs or incorrect validity periods, that might cause SSL errors during installation or operation
• Certificate Renewal Management: Decode and check certificate expiration dates to avoid service disruptions caused by expired certificates

For Security Professionals

• Incident Response: Analyze certificates during security incidents to confirm their authenticity and identify potential misuse or tampering
• Certificate Inspection: Decode certificates received from external parties to verify their legitimacy before trusting or integrating them into your infrastructure

For Educational Purposes

• Learning About Certificates: Help developers, engineers, and students understand the structure and components of digital certificates by presenting the data in a clear, readable format
• Training on Certificate Management: Use the tool in training sessions to demonstrate how to decode and verify certificate details effectively

For Website Owners and Businesses

• Building User Trust: Verify that SSL certificates installed on websites are correctly configured, ensuring secure connections for users and fostering trust
• Compliance with Best Practices: Regularly inspect certificates to maintain compliance with industry standards like X.509
• Preventing Misconfigurations: Double-check certificate details before installation to avoid costly mistakes such as installing the wrong certificate on a server