HomeRSA Key Pair Generator

RSA Key Pair Generator

Online RSA key pair generator with custom key sizes and local PEM public/private key output for certificate setup, integration debugging, and development testing.


Generation Settings

Generate PEM RSA public and private keys with the browser Web Crypto API. No key material is uploaded by this tool.

Common Presets

Supported range: 256-16384 bits, and the value must be a multiple of 8.

2048 or 4096 bits are recommended. Larger sizes usually take longer to generate.

Generation Notes

  • Key generation runs entirely inside the current browser.
  • Generating a new key pair replaces the current result, so copy anything you need first.
  • Private keys are sensitive. Save them to a trusted location as soon as possible.
Ready to generate a new RSA key pair.

Result Summary

All data stays in the browser

Algorithm

RSASSA-PKCS1-v1_5

Hash

SHA-256

Key Size

Elapsed Time

Export Format

PEM / PKCS8 / SPKI

Typical Usage

Certificate setup, signature testing, integration debugging

Key Output

Public Key

Safe to share or add to server-side configuration

The PEM public key appears here after generation

Private Key

Store and transmit the private key only in trusted environments

The PEM private key appears here after generation


Documentation

What is RSA Key Pair Generator

RSA Key Pair Generator creates PEM-formatted RSA public and private keys directly in the browser for certificate setup, signature testing, integration debugging, and development preparation.

Key Features

  • Supports custom RSA key sizes.
  • Includes common presets for 2048, 3072, and 4096 bits.
  • Outputs PEM public and private keys ready to copy.
  • Runs locally in the browser without external API calls.

Steps

  1. Enter a key size or choose a common preset.
  2. Click Generate Key Pair to create a new RSA public and private key.
  3. Use Copy Public Key or Copy Private Key to get the PEM output.
  4. Save the private key in a secure location before continuing with certificate or signing work.

Use Cases

  • Preparing keys before certificate requests.
  • Debugging API signing and signature verification.
  • Creating temporary keys for local development environments.
  • Preparing RSA examples for demos, training, or test systems.

Notes

  • The supported range is 256 to 16384 bits, and the value must be a multiple of 8.
  • 2048 or 4096 bits are usually the better options. Larger sizes take longer to generate.
  • The generated key pair uses RSASSA-PKCS1-v1_5 with SHA-256 and can be exported as PEM.
  • Private keys are sensitive and should never be shared in repositories, chats, or public pages.

FAQ

Why does generation become slower with larger sizes?

Larger RSA modulus sizes require more browser-side computation. On slower devices, 8192 bits and above can take noticeably longer.

Is any generated key material uploaded to a server?

No. The tool uses the browser Web Crypto API locally and does not upload generated keys by default.

How are the public and private keys typically used?

The public key is usually shared for verification or configuration, while the private key is used for signing or decryption and must be stored securely.