Generate RSA Keys

About Generate RSA Keys

Public-key cryptography uses two mathematically linked keys instead of one shared secret: a public key that can be freely shared and used by anyone to encrypt a message, and a private key kept secret that alone can decrypt it. This solves the key-distribution problem that plain symmetric encryption (like AES) can't — two people can securely exchange encrypted messages without ever having met to agree on a shared passphrase.

This tool generates a real RSA keypair (2048-bit or 4096-bit) using your browser's native Web Crypto API, exported in standard PEM format — the same widely-supported text format used across TLS certificates, SSH, and countless other systems. Both keys are generated locally; the private key never leaves your browser.

Important distinction: this generates standard PEM-format RSA keys, not the OpenPGP packet and ASCII-armor format used by tools like GnuPG or classic PGP software. Building a genuinely spec-compliant OpenPGP implementation from scratch is a substantial undertaking with real correctness risk — if you specifically need OpenPGP-format keys for email encryption or GPG-compatible signing, use a dedicated tool like GnuPG or the OpenPGP.js library instead.

This is useful for learning how public-key cryptography works hands-on, generating a keypair for custom encryption experiments or development testing, and any project that specifically needs standard PEM-format RSA keys rather than the OpenPGP format.

How it works

1. Choose a key size. 2048-bit (fast, standard) or 4096-bit (stronger, slower to generate).
2. Click Generate keypair. A real RSA keypair is generated using the Web Crypto API.
3. Save both keys immediately. Nothing is stored — copy them before leaving the page.