Convert Your PEM Files to DER

This free online tool quickly changes the encoding and extension of your PEM (base64) certificates, keys, and CSR files to DER (binary). Because this converter runs entirely client-side, nothing leaves your browser or is saved to our server.

Convert Online (Browser-Based)

Upload PEM File (.pem, .crt, .cer, .key, .txt) *

Convert Files to DER Format Using OpenSSL or Bash (Linux/Unix)

Convert your PEM encoding and/or file extension (.pem) to DER (.der) using the following terminal command. (Replace placeholder values with your actual filenames and input file extension [if different than .pem].)

Select the type of PEM file you want to convert (only one file type can be selected at a time):

Certificate File

Private Key File

CSR File

OpenSSL/Bash (Linux/Unix) Command:

openssl x509 -outform DER -in certificate.pem -out certificate.der