PEM (Privacy Enhanced Mail) Base64 encoded DER certificate, enclosed between "-----BEGIN CERTIFICATE-----" and "-----END CERTIFICATE-----". In order to see the PEM representation for an existing certificate, open the certificate (click on Menu File > Open > Open Certificate) and click on PEM button.

You can copy the content of the PEM certificate representation by clicking on Copy button.

Abstract Syntax Notation One (ASN.1) is a standard and flexible notation that describes data structures for representing, encoding, transmitting, and decoding data. DER(Distinguished Encoding Rules) is a subset of Basic Encoding Rules (BER) is used in situations when a unique encoding is needed, such as in cryptography and ensures that a data structure that needs to be digitally signed produces a unique serialized representation.

In order to see the ASN.1 representation for an existing certificate, open the certificate (click on Menu File > Open > Open Certificate) and click on ASN.1 button. You can copy the content of the ASN.1 certificate representation by clicking on Copy button.