CSR stands for Certificate Signing Request — the file you submit to a Certificate Authority (CA) to request an SSL certificate. It contains domain information and a public key.

Is the CSR I enter sent to a server?

No. ASN.1 DER parsing is performed entirely in your browser.

Do I need to enter a private key into this tool too?

No. A CSR only contains a public key, so no private key input is needed.

📜 CSR Viewer

Paste a PEM-format (-----BEGIN CERTIFICATE REQUEST-----) CSR to see its details.

CSR PEM

How to use

Paste a PEM-format CSR.
Click "Check".
The subject and public key information are displayed.

🎯 Use Cases

Verify CSR contents before applying for an SSL certificate
Identify the correct file among several CSR files
Check the public key length (bit size)

Example

Input

Output

Version                v1
Subject                C=US, ST=California, L=San Francisco, O=Example Inc, CN=example.com
Public Key Algorithm   RSA (2048 bit)

Result of pasting an RSA 2048-bit CSR for example.com. The tool parses the ASN.1 DER entirely in your browser (no upload) and lays out the version, subject, and public key algorithm as a table.

FAQ

What is a CSR?: CSR stands for Certificate Signing Request — the file you submit to a Certificate Authority (CA) to request an SSL certificate. It contains domain information and a public key.
Is the CSR I enter sent to a server?: No. ASN.1 DER parsing is performed entirely in your browser.
Do I need to enter a private key into this tool too?: No. A CSR only contains a public key, so no private key input is needed.