RSA Key Pair Generator
Generate RSA keys in your browser, then copy SPKI public and PKCS#8 private keys as PEM or download the pair for signing and verification tests.
RSA Key Pair Generator
Generate RSA keys in your browser, then copy SPKI public and PKCS#8 private keys as PEM or download the pair for signing and verification tests.
About RSA key generation
Generated with Web Crypto
The tool calls browser SubtleCrypto to generate an RSASSA PKCS1 v1.5 key pair with SHA-256 and public exponent 65537. You can choose 1024, 2048, 3072, or 4096-bit modulus lengths, and unsupported browsers will show an error instead of falling back to a weaker generator.
PEM output for development workflows
The public key is exported as SPKI PEM and the private key as PKCS#8 PEM, then shown for copy or download. This is not OpenSSH key format, not a certificate, and not a replacement for production key management, rotation, or hardware-backed storage.
FAQ
Common questions and answers about this topic.
What is an RSA key pair?
An RSA key pair has a public key and a private key used by public-key cryptography schemes. This page generates a signing-capable browser key pair and exports it as PEM for development and testing.
What key sizes are supported?
You can choose 1024, 2048, 3072, or 4096 bits; the default is 2048 bits. Changing the size generates a fresh pair. Larger keys can take longer to generate.
What PEM formats do the public and private keys use?
The public key uses SPKI with a BEGIN PUBLIC KEY header; the private key uses PKCS#8 with a BEGIN PRIVATE KEY header. These are not PKCS#1 RSA PUBLIC KEY or RSA PRIVATE KEY blocks, OpenSSH keys, or certificates. Check the format required by the application importing them.
Is the downloaded private key encrypted or password-protected?
No. The PKCS#8 private key is exported as unencrypted PEM; Base64 encoding is not encryption. The bottom download control saves both the public and private keys in one .pem file. Treat that file as private-key material and do not publish or share it as though it contained only a public key.
Is it safe to generate keys in the browser?
The tool uses your browser's Web Crypto API and does not upload the generated keys. It is intended for development and testing; production key management, rotation, and protected storage are outside its scope.
Is my data sent to any server?
RSA key generation runs locally in your browser; the tool does not send the generated keys to a server. Copy and download actions export the keys you choose, while the share action shares the page URL, not the key contents.