Check CSR

About Check CSR

CSR Decoder—Decode Certificate Signing Requests Instantly Online

Free Online CSR Decoder Tool—Analyze Your Certificate Signing Request

The CSR Decoder is a secure tool for decoding Certificate Signing Requests (CSRs) in PEM format. It shows detailed info like the Common Name (CN), Organization, Country, Public Key, and Key Algorithm. This tool is key for checking CSR accuracy before sending it to a Certificate Authority (CA).

It's vital for getting an SSL certificate for websites, servers, or apps. Decoding the CSR makes sure all details are correct, avoiding certificate issuance errors.

What Is a Certificate Signing Request (CSR)?

A CSR is a text block made on the server for an SSL certificate. It has identifying info and a public key, signed with a private key. The CA uses it to create a certificate that fits your request.

Key Components of a CSR:

Common Name (CN) – The fully qualified domain name (FQDN)
Organization Name (O) – Legal entity name
Organizational Unit (OU) – Division or department
Country (C) – Two-letter ISO country code
State or Province (ST) – State or region name
Locality (L) – City or town
Email Address – Contact email (optional)
Public Key – The public portion of your key pair
Signature Algorithm – e.g., SHA256 with RSA

How to Use the Online CSR Decoder

Paste your CSR in PEM format into the decoder text box:
cssCopyEdit-----BEGIN CERTIFICATE REQUEST----- MIICzjCCAbYCAQAwgYExCzAJBgNVBAYTAlVTMQswCQYDVQQIDAJDQTESMBAGA1UE... -----END CERTIFICATE REQUEST-----
Click “Decode” to instantly extract and display the CSR fields.
Review the decoded information for accuracy.
Use the decoded data to validate your request before submitting to a CA.

CSR Decoder Output Details

Field	Description
Common Name (CN)	Domain name for which the certificate is requested
Organization (O)	Official company or entity name
Organizational Unit (OU)	Internal department, optional
City/Locality (L)	City where the entity is located
State/Province (ST)	State or region
Country (C)	Country code (e.g., US, IN, GB)
Email Address	Contact email, if provided
Public Key	RSA or ECC public key used for encryption
Key Size	Typically 2048 or 4096 bits for RSA
Signature Algorithm	Cryptographic algorithm used to sign CSR

Diagram: CSR Creation and Decoding Flow

graph TD A[User generates CSR on server] --> B[CSR created with public key + details] B --> C[Submit to CA] B --> D[Paste into CSR Decoder] D --> E[Decode details] E --> F[Review CN, O, OU, etc.]

Why Use a CSR Decoder?

✅ Verify CSR Details Before Certificate Issuance

Make sure your CSR is correct before getting a certificate.

?️ Confirm Cryptographic Parameters

Check the key strength, algorithm, and field format are right.

? Troubleshoot Certificate Issues

Find out why certificates might have wrong info by decoding the CSR.

? Validate Third-Party CSR Submissions

CA agents or IT admins can check CSRs from clients or remote servers.

CSR Formats Supported

Format	Description
PEM	Base64 encoded with BEGIN CERTIFICATE REQUEST header
PKCS#10	Most common format for SSL CSRs
SPKAC	Used by some browsers (e.g., for client certificates)

Note: This tool mainly supports PKCS#10 CSRs in PEM format.

Frequently Asked Questions

? Is it safe to use this CSR decoder?

Yes. It works locally in your browser. No data is sent or stored.

? Can I decode CSRs generated from any server?

Yes. You can decode CSRs from Linux, Windows, cPanel, Plesk, Java Keystores, and more, as long as they're in PEM format.

? Can I decode expired CSRs?

CSRs don't expire. You can decode any valid CSR, even if it's old.

?️ How do I generate a CSR?

To make a CSR, use OpenSSL:

openssl req -new -newkey rsa:2048 -nodes -keyout yourdomain.key -out yourdomain.csr

Security Best Practices for CSR and Private Key Handling

Always make CSRs on the server where the certificate will go.
Never share your private key.
Keep keys safe with access limits.
Use at least 2048-bit RSA or ECC keys (P-256/P-384) for better security.

Conclusion – Decode CSRs with Confidence

Our free, browser-based CSR Decoder lets you check and validate your Certificate Signing Requests quickly. It ensures your SSL certificates are accurate, compliant, and secure for any platform or server. With clear decoding and no data sent, this tool offers full visibility and trust in your SSL request process.