How to Decode CSRs and Certificates Locally (Offline).

If your CSR or certificate contains sensitive information that you do not want to send over the Internet (such as a challenge passphrase or private organisational details), you should decode it locally on your own machine.

Option 1: SslDecoder Desktop

SslDecoder Desktop is a secure Windows application designed specifically for decoding CSRs and certificates in secure environments. It provides a user-friendly interface and guarantees that no data ever leaves your computer.

Key benefits:

  • Easy-to-use graphical interface
  • No network communication — all data stays local
  • Ideal for air-gapped and classified systems
  • Free 30-day trial with expert support

Request Free Trial

Option 2: OpenSSL Command-Line

If you prefer a command-line tool, you can decode a CSR locally using OpenSSL: 

openssl req -in server.csr -noout -text

This command will display the contents of your CSR without sending any data over the network.

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