Cert Decoder is a free, browser-based tool designed to decode X.509 SSL/TLS certificates in PEM format. It provides detailed insights into certificate attributes, including:
Issuer
Validity period
Subject Alternative Names (SAN)
Serial number
Fingerprint, and more.
Operating entirely on the client-side, Cert Decoder ensures that all decoding processes occur securely within your browser, safeguarding your privacy by eliminating any data transmission to external servers.
Whether you’re a developer, security professional, or simply need quick access to SSL/TLS certificate details, Cert Decoder offers a fast, secure, and reliable solution without compromising sensitive information.