Are my generated keys secure?

Yes. The keys are generated entirely in your browser using local cryptographic APIs and are never sent to any server.

What is the difference between PKCS#8 and PKCS#1?

PKCS#8 is a modern, generic standard that supports passphrase encryption in this tool, while PKCS#1 is an older, RSA-specific format.

Which key size should I choose?

2048 bits is the standard baseline for most applications, while 4096 bits offers stronger, long-term security at the cost of slower performance.

Can I encrypt a PKCS#1 private key with a passphrase here?

No, passphrase encryption in this tool is only supported for the PKCS#8 format.

What format is the generated public key?

The public key is always generated in the standard SPKI format, labeled as 'PUBLIC KEY'.

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Security

RSA Key Pair Generator

Generate an RSA key pair (2048/3072/4096-bit) as PEM-encoded public and private keys. Optionally encrypt the private key with a passphrase. PKCS#8 (recommended) or PKCS#1 private key format. Everything runs locally.

Details

What this tool helps you do

Produces a matching RSA public/private key pair using Node's crypto.generateKeyPairSync().

Key size: 2048 (the modern baseline), 3072, or 4096 bits. Larger = more security but slower. 2048 is fine for most uses; use 4096 for long-term protection.
Private key format:
PKCS#8 (recommended) — generic format, works everywhere, supports passphrase encryption.
PKCS#1 — RSA-specific (older), label RSA PRIVATE KEY. Cannot be encrypted with a passphrase in this tool.
Passphrase: if provided, the private key is encrypted (AES-256-CBC) and cannot be used without it.

The public key is always SPKI format (PUBLIC KEY).

Use cases: setting up HTTPS, JWT signing keys, SSH from RSA, learning asymmetric crypto. The keys are generated locally and never transmitted.

Execution

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Result

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Samples

RSA Key Pair Generator

What this tool helps you do

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Key facts

Overview

When to use

How it works

Use cases

Examples

1. Generate Standard JWT Signing Keys

2. Secure SSH Key Generation with Passphrase

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