Self-Signed SSL Certificate Generator
Generate self-signed X.509 SSL certificates and RSA private keys directly in your browser for local development and staging.
1 How to Use the Self-Signed SSL Certificate Generator
Enter your Common Name / Domain (e.g. 'localhost' or 'dev.local') and organization name.
Choose validity duration in days (e.g. 365 days).
Click 'Generate Self-Signed Certificate'. Browser creates an RSA keypair and self-signs the certificate.
Download 'cert.crt' and 'key.key' directly to configure your local Apache, Nginx, or Node server.
2 Technical Specifications
| Specification | Details & Capabilities |
|---|---|
| Standard | X.509 v3 Self-Signed Certificate |
| Key Type | 2048-bit RSA Private Key |
| Signature Algorithm | SHA-256 with RSA Encryption |
| Output Files | PEM-encoded cert.crt and key.key with 1-click download |
Trust and Privacy
100% Client-Side Privacy Guarantee
All calculations run directly in your local browser memory. Zero data is ever transmitted, logged, or stored on remote servers.
4 Frequently Asked Questions
Q. Can I use a self-signed certificate on a production public website?
No. Browsers will show an untrusted certificate warning because the certificate is not signed by a recognized Certificate Authority (CA). Use free Let's Encrypt for public sites.
Q. Where are self-signed certificates used?
They are ideal for local software development, Docker containers, internal intranet services, and IoT device testing.