CSR Generator - Generate Certificate Signing Requests Online
Professional CSR generator to create Certificate Signing Requests with private and public keys for SSL/TLS certificates instantly. Support for RSA and ECDSA key types with client-side security.
How to Generate a CSR - Step by Step Guide
Enter Your Certificate Information
Fill in your organization and domain details. The Common Name (CN) is required and should be your fully qualified domain name (FQDN):
Example: Certificate Information
Configure Key Settings
Choose your cryptographic key type and size. The tool supports both RSA and ECDSA (Elliptic Curve) keys:
Key Type Comparison
| Key Type | Key Size | Security Level | Performance |
|---|---|---|---|
| RSA | 2048 bits | ✓ Standard | Good |
| RSA | 4096 bits | ✓ High | Slower |
| ECDSA | P-256 | ✓ Standard | Excellent |
| ECDSA | P-384 | ✓ High | Very Good |
Generate Your CSR and Keys
Click "Generate CSR" to create your certificate signing request along with the cryptographic key pair:
Example: Generated CSR
Your CSR will look like this (PEM format):
-----BEGIN CERTIFICATE REQUEST----- MIICwzCCAasCAQAwfjEUMBIGA1UEAxMLZXhhbXBsZS5jb20xCzAJBgNVBAYTAlVT MRMwEQYDVQQIEwpDYWxpZm9ybmlhMRYwFAYDVQQHEw1TYW4gRnJhbmNpc2NvMRQw EgYDVQQKEwtFeGFtcGxlIEluYzEWMBQGA1UECxMNSVQgRGVwYXJ0bWVudDCCASIw DQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAPOllsQL5vlhPBN7TCzsza7idwqJ +hCkHNj0fyO8PwLQu4+23LPS7N2aBZYjN1uBS/Gn55aJwDq0KY0p45TnVNtzDuVE ... -----END CERTIFICATE REQUEST-----
Download and Secure Your Keys
Save your generated files securely. The private key is especially important:
Your private key is the secret that proves ownership of your certificate. Never share it, commit it to version control, or upload it to any website. Store it in a secure location with restricted access. You'll need it to install your SSL/TLS certificate once it's issued by the Certificate Authority.
Submit CSR to Certificate Authority
Take your generated CSR to a Certificate Authority (CA) to get your SSL/TLS certificate issued:
Frequently Asked Questions
What is a CSR (Certificate Signing Request)?
A CSR is an encoded message sent to a Certificate Authority (CA) to apply for an SSL/TLS certificate following PKCS#10 standard. It contains your public key and information about your organization and domain. The CA uses the CSR to create your certificate while you keep the private key secure.
Is it safe to generate a CSR online?
Yes! Our CSR generator runs entirely in your browser using the Web Crypto API. Your private key never leaves your computer and is not sent to any server. However, always download and secure your private key immediately after generation following NIST key management guidelines.
Should I use RSA or ECDSA keys?
Both are secure. RSA is more widely supported and traditional. ECDSA offers equivalent security with smaller key sizes and better performance. For most use cases, RSA 2048-bit or ECDSA P-256 are excellent choices. Check with your Certificate Authority for their recommendations.
What are Subject Alternative Names (SANs)?
SANs allow one certificate to cover multiple domain names. For example, a certificate with SANs can protect example.com, www.example.com, and api.example.com. This is more convenient and cost-effective than having separate certificates for each domain.
What do I do after generating the CSR?
1) Download and securely store your private key. 2) Submit the CSR to your chosen Certificate Authority like Let's Encrypt, DigiCert, or Sectigo. 3) Complete domain validation as required by the CA. 4) Receive your signed certificate. 5) Install the certificate on your server along with the private key you generated.
Can I regenerate a CSR if I lose my private key?
If you lose your private key, you must generate a new CSR with a new key pair. The CSR and certificate are cryptographically linked to the private key. Without the private key, your certificate cannot function. Always keep secure backups of your private keys.
What file format is the generated CSR?
The CSR is generated in PEM (Privacy Enhanced Mail) format, which is the standard format expected by most Certificate Authorities. It's a Base64-encoded format with BEGIN and END markers. The private and public keys are also in PEM format.
How long does the CSR generation take?
CSR generation typically takes just a few seconds. RSA 2048-bit keys generate almost instantly. Larger keys (RSA 4096-bit) may take a few seconds longer. The process happens entirely in your browser using modern cryptographic APIs.
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