Self-Signed Certificate Generator
Generate self-signed X.509 SSL/TLS certificates and RSA private keys directly in your browser. Cryptographically secure and entirely offline.
What is a Self-Signed Certificate?
A self-signed certificate is an SSL/TLS certificate that is signed by the person or organization that created it, rather than by a trusted public Certificate Authority (CA) like Let's Encrypt, DigiCert, or GoDaddy. It contains the exact same cryptographic properties as a CA-signed certificate but lacks the chain of trust.
When to use it? (Testing, Internal APIs, VPNs)
Self-signed certificates are highly useful for specific, controlled environments. They are ideal for Testing and Development environments where deploying a real certificate is unnecessary. They are also widely used in Internal APIs, Microservices, and Intranets where traffic doesn't leave the corporate network. Additionally, they are perfect for encrypting VPN tunnels (like OpenVPN) and securing backend database connections.
Why is it unsafe for public websites? (Browser warnings)
When a regular user connects to a website, their browser checks if the certificate is signed by a CA in its trusted root store. Because a self-signed certificate is self-verified, browsers like Chrome or Firefox will immediately block the connection and display a severe "Your connection is not private" or "SEC_ERROR_UNKNOWN_ISSUER" warning. For public-facing production websites, always use a free or paid certificate from a recognized CA.