About Self-Signed Certificate Generator
Generate self-signed SSL/TLS certificates for local development and testing. Create certificates with custom Subject Alternative Names (SANs) for localhost, IP addresses, and custom domains. Perfect for setting up HTTPS in development environments. All keys are generated locally in your browser.
How to Use
- 1Enter hostname (e.g., localhost)
- 2Add Subject Alternative Names for additional domains/IPs
- 3Set validity period and key size
- 4Click Generate Certificate
- 5Download certificate and private key
- 6Configure your server to use the generated files
Key Features
- Subject Alternative Names (SAN) support
- DNS names and IP addresses in SANs
- Configurable validity period (30 days to 10 years)
- RSA key generation (2048/3072/4096 bits)
- CA certificate option for signing other certs
- Combined PEM download option
- Server configuration examples
Common Use Cases
Frequently Asked Questions
Why do browsers show a warning?
Self-signed certificates are not trusted by browsers because they are not issued by a known Certificate Authority. This is normal for development use.
Can I use this in production?
No. Self-signed certificates should only be used for development and testing. For production, use certificates from a trusted CA like Let's Encrypt.
Privacy First
All processing happens directly in your browser. Your files never leave your device and are never uploaded to any server.
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