Generate Self-Signed Certificate Online - Free SSL/TLS X.509 Certificate Generator

Self-Signed Certificate Generator

Generate self-signed SSL/TLS X.509 certificates for testing and development. Creates a private key, CSR, and self-signed certificate.

OpenSSL-powered Generation
Certificate Details

Certificate Information

Domain name or server hostname

2-letter ISO country code

Generated Output

Certificate Files

About Self-Signed Certificates

A self-signed certificate is an SSL/TLS certificate that is signed by its own private key rather than a trusted Certificate Authority (CA). They are commonly used for:

Note: Self-signed certificates will trigger browser warnings and should not be used for production public-facing websites. For production, use certificates from trusted CAs like Let's Encrypt.

How to Use

  1. Enter the Common Name (CN) - typically your domain name
  2. Fill in optional organization details for the certificate subject
  3. Select the signature algorithm and key size
  4. Set the validity period (default: 365 days)
  5. Click Generate Certificate
  6. Download individual files or use Download All (ZIP)

Installing the Certificate

Apache:

SSLCertificateFile /path/to/certificate.crt SSLCertificateKeyFile /path/to/private_key.key

Nginx:

ssl_certificate /path/to/certificate.crt; ssl_certificate_key /path/to/private_key.key;

Node.js:

const https = require('https'); const fs = require('fs'); const options = { key: fs.readFileSync('private_key.key'), cert: fs.readFileSync('certificate.crt') }; https.createServer(options, app).listen(443);
Try other encryption, hashing, and signing utilities.