Which key size should I choose?

2048 bits is a common default. Choose 3072 or 4096 bits for stronger, longer-term security at the cost of slower operations.

What format are the keys in?

The public key uses SPKI PEM and the private key uses PKCS#8 PEM, which most libraries and tools accept.

Are the keys uploaded?

No. They are generated locally with the Web Crypto API and never sent anywhere.

Security & Cryptography

RSA Key Pair Generator

Generate an RSA public and private key pair in PEM format.

Free browser toolRuns in your browserNo sign-up

Key size

Keys are generated in your browser with the Web Crypto API and never leave your device. Keep the private key secret and share only the public key.

100% private - runs entirely in your browser.

Your input, keys and passwords are never uploaded. Want proof? Load this page, then turn off your internet - the tool still works. For an exact check, open your browser's DevTools Network tab and confirm no data is sent when you use it.

About the RSA Key Pair Generator

Generate an RSA key pair with a public key and a private key in standard PEM format.

Choose 2048, 3072 or 4096 bits, then copy the keys for use with signing, verification and encryption.

Keys are generated in your browser with the Web Crypto API and never leave your device.

Key features

2048, 3072 or 4096-bit keys
Public key in SPKI PEM, private in PKCS#8 PEM
Copy each key with one click
Runs entirely in your browser

How to use

1Choose a key size.
2Click generate to create the pair.
3Copy the public and private keys.

Examples

2048-bit pair

Input: 2048 bits

Output: PUBLIC KEY and PRIVATE KEY blocks

The public key can be shared; keep the private key secret.

Stronger key

Input: 4096 bits

Output: A larger, slower but stronger key pair

Higher bit sizes are harder to break but slower to use.

Frequently asked questions

Which key size should I choose?: 2048 bits is a common default. Choose 3072 or 4096 bits for stronger, longer-term security at the cost of slower operations.
What format are the keys in?: The public key uses SPKI PEM and the private key uses PKCS#8 PEM, which most libraries and tools accept.
Are the keys uploaded?: No. They are generated locally with the Web Crypto API and never sent anywhere.

Open a related tool to prepare your files or refine the finished result.