Base 64 Certificate
Obtain the certificate in base 64.
JSON Web Key
Obtain the JWK to validate the request.
Private Key
Obtain the private key to sign requests.
Extract information from a certificate
Read the blog post that explains what the tool is doing at https://darthseldon.net/certificate-reader/
Warning! I will never keep the certificate you upload, it will only read the cert and return it to you via HTTPS.