What key size should I use?
2048 bits is the current minimum recommendation for most uses; 3072 or 4096 bits for longer-term or higher-security needs. Larger keys are slower to generate and use.
RSA Key Pair Generator
Configuration
Keys are generated locally with the Web Crypto API (RSASSA-PKCS1-v1_5, SHA-256, exponent 65537) and never leave your browser.
Generated key pair
Generate to see the key pair here.
About this RSA Key Pair Generator
Generate a real RSA public/private key pair locally with the Web Crypto API, in PEM or DER (hex) format.
Keys are generated locally in your browser using the Web Crypto API's RSASSA-PKCS1-v1_5 algorithm and never leave it. The private key is never included in a share link — only the key size and format travel that way.
FAQ
Is it safe to generate a real production key pair with an online tool?
Be cautious — generate keys for TLS certificates, SSH, or production signing on a secure machine with your own tooling. Use an online generator mainly for learning, testing, and prototyping — and specifically one that's verifiably client-side, like this one.
What's the difference between the public and private key?
The public key can be shared freely — it encrypts data or verifies signatures. The private key must stay secret — it decrypts data or creates signatures. Never share or upload it.
Does this generate PKCS#1 or PKCS#8 keys?
PKCS#8 for the private key (-----BEGIN PRIVATE KEY-----) and SPKI for the public key — the modern, algorithm-agnostic standard most current software expects. PKCS#1's legacy -----BEGIN RSA PRIVATE KEY----- format isn't offered here; if a tool specifically requires it, convert with openssl rsa -in key.pem -traditional.
What is RSA actually used for?
SSH authentication, TLS/SSL certificates, JWT signing (RS256), code signing, and email encryption (PGP/GPG).
Does my private key ever leave my browser?
No — key generation runs entirely client-side using the Web Crypto API; nothing is transmitted or logged.
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