Cert Decoder

Project Description

Cert Decoder is a free online tool that decodes X.509 SSL/TLS certificates in PEM format. It allows users to instantly extract and verify crucial certificate details such as issuer, validity period, Subject Alternative Names (SAN), serial number, and fingerprint. A key feature is that all processing happens securely within the user's browser, ensuring no data is transmitted to external servers. The tool is user-friendly, requiring only the pasting of a PEM-encoded certificate to initiate the decoding process. It provides a clear, well-formatted table of the decoded information and includes a helpful explanation of X.509 certificates. Cert Decoder stands out for its simplicity, security, and comprehensive output, making it a valuable resource for anyone needing to quickly analyze and verify SSL/TLS certificates.