It parses a raw PEM-encoded certificate string and extracts its human-readable metadata, including the issuer, subject, validity dates, and extensions.

Yes. This tool runs 100% locally in your browser. It does not send your certificate to any server. Furthermore, public certificates do not contain private keys.

PEM is the most common format for SSL certificates. It is a Base64-encoded ASCII file that begins with "-----BEGIN CERTIFICATE-----".

No, this tool is specifically designed to decode public x509 certificates, not private keys or certificate signing requests (CSR).

System administrators often need to decode a raw certificate to verify its expiration date and SANs (Subject Alternative Names) before installing it on a production server.

Yes, the SSL DECODER tool is completely free with no usage limits, sign-ups, or subscriptions required.

No. We do not store or log any of the URLs, domains, or passwords you check using our tools.

Boost Your Business Online