Enter a website URL ... see its certificate info.
A TLS connection from your browser to a website is an encrypted connection utilizing asymmetric cryptography. The server establishes a public/private keypair, signs messages using its private key and the client (your browser) decrypts them using the server's public key.
x.509 is a standard format defining metadata that is part of the public key. If you enter in a website, the tool will pull the public x.509 certificate and show the metadata.
The public x.509 server certificate is meant to be public so that clients such as web browsers can verify the authenticity of the server.
version 0.4