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Free Online RSA Key Generator

Generate RSA key pairs, encrypt with public keys, decrypt with private keys. Asymmetric cryptography in your browser.

What is RSA Encryption?

RSA (Rivest-Shamir-Adleman) is an asymmetric encryption algorithm that uses a pair of keys: a public key for encryption and a private key for decryption. Unlike symmetric encryption (AES), RSA allows anyone to encrypt a message using your public key, but only you can decrypt it with your private key.

This tool uses RSA-OAEP with SHA-256 for optimal security. Key pairs are generated using the Web Crypto API's cryptographically secure random number generator.

Key Features

2048 & 4096-bit Keys

Generate industry-standard key lengths for different security requirements.

RSA-OAEP + SHA-256

Uses the most secure RSA padding scheme with SHA-256 hashing.

Encrypt & Decrypt

Full workflow: generate keys, encrypt with public key, decrypt with private key.

PEM Export

Download keys in standard PEM format compatible with OpenSSL and other tools.

Frequently Asked Questions

Are my keys safe?
Yes. Key generation and all cryptographic operations happen entirely in your browser. Nothing is sent to any server.
What's the max message size?
RSA can only encrypt small messages. For 2048-bit keys with OAEP-SHA256, the max is ~190 bytes. For larger data, use AES and encrypt the AES key with RSA (hybrid encryption).
2048 or 4096-bit?
2048-bit is considered secure through 2030+. 4096-bit provides extra margin but is slower to generate. Use 2048 for most purposes.
Are the keys compatible with OpenSSL?
Yes. The public key is exported in SPKI format and private key in PKCS8 format, both standard PEM-encoded.

Need symmetric encryption?

Try our AES Encrypt/Decrypt tool for fast symmetric encryption with AES-GCM, CBC, or CTR modes.

AES Tool

About the RSA Key Generator

The RSA Key Generator is a free online tool that lets you generate RSA key pairs, encrypt and decrypt with public/private keys. It runs entirely in your browser with no sign-up required, so you get instant results while your data stays on your device. It is built for developers, designers, and anyone who needs a fast, reliable rsa key generator without installing software.

How to use the RSA Key Generator

  1. 1Open the RSA Key Generator and enter or paste your input.
  2. 2Adjust the available options to match what you need.
  3. 3View the result instantly as you work.
  4. 4Copy or download the output to use in your project.

Frequently asked questions

Is the RSA Key Generator free to use?

Yes. The RSA Key Generator is completely free with no account, sign-up, or installation required.

Is my data private when I use the RSA Key Generator?

This tool runs entirely in your browser. Your data is never uploaded to a server, which makes it safe to use with sensitive input.

Do I need to install anything?

No. The RSA Key Generator works in any modern web browser on desktop or mobile, with nothing to download.

Can I use the RSA Key Generator on mobile?

Yes. The tool is responsive and works on phones, tablets, and desktops.

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