RSA Key Generator

What is RSA Key Generator?

RSA Key Generator creates public-private key pairs in PEM format using standard key sizes (2048, 3072, 4096 bits) with configurable exponent values. It generates keys using the Web Crypto API's secure random number generator, outputs both PKCS#1 and PKCS#8 formats, and extracts the public key components (modulus and exponent) for inspection. The tool includes fingerprint calculation (SHA-256) for key identification and supports generating Certificate Signing Requests (CSR) from the generated keys.

DevOps engineers setting up SSH and TLS infrastructure, security engineers generating test certificates, and backend developers implementing RSA-based authentication. The tool runs entirely in your browser — your data never leaves your device.

How to Use RSA Key Generator

1. Select the key size — 2048 (minimum recommended), 3072, or 4096 bits
2. Choose the output format — PKCS#1 (RSA-specific) or PKCS#8 (generic)
3. Generate the key pair and review the public and private keys in PEM format
4. Copy the keys separately and store the private key securely

Common Use Cases

• Generating RSA key pairs for SSH authentication setup on servers
• Creating test key pairs for development and staging environments
• Generating keys for JWT RS256 signing in authentication systems
• Producing key pairs for client certificate authentication testing

Pro Tips

• 2048-bit RSA is considered secure through approximately 2030 — for long-lived keys (CA roots, code signing), use 4096 bits; for short-lived keys (TLS sessions, JWTs), 2048 provides adequate security with better performance
• Never use keys generated in a browser for production — browser-generated keys are suitable for development and testing, but production keys should be generated on secure systems with audited entropy sources like HSMs
• The public exponent 65537 (0x10001) is standard because it has only two set bits, making modular exponentiation efficient; changing it has no security benefit and may break compatibility with some implementations

Why Use This Tool?

• Privacy-first: All processing happens locally in your browser. No data is transmitted to any server.
• No installation required: Works in any modern browser on desktop or mobile.
• Completely free: No account, no credit card, no usage caps.
• Fast and reliable: Powered by modern Web APIs for near-instant results.

Related Concepts

Learn more about related topics: Public key cryptography, PEM format, PKCS#8, Key fingerprint.

Frequently Asked Questions