Self-Signed Certificate Generator

Generate a self-signed X.509 certificate directly in your browser. Perfect for localhost, development servers, and testing environments.

Your private key never leaves your device

Subject Information

The identity that will be bound to the certificate

Primary domain name or identifier for this certificate

Organization Details

Optional information about your organization

2-letter code

Subject Alternative Names

Additional identities the certificate will be valid for

No DNS names added

No IP addresses added

Certificate Configuration

Validity period for your self-signed certificate

How long the certificate will be valid. For development, 1 year is typical.

Key Configuration

Cryptographic algorithm for your key pair

ECDSA offers better security with smaller key sizes. RSA is more widely compatible.