RSA keys are based on the difficulty of factoring large prime numbers. They are versatile, supporting both encryption and signing. EC (Elliptic Curve) keys offer equivalent security with much smaller key sizes—a 256-bit EC key provides comparable security to a 3072-bit RSA key. EC keys are faster to generate and require less computational power, making them ideal for mobile and IoT devices.

2048-bit: Minimum recommended by NIST for general use through 2030.
3072-bit: Recommended for stronger security, equivalent to 128-bit symmetric security.
4096-bit: Maximum security, suitable for long-term secrets or regulatory compliance. Note that 4096-bit key generation is significantly slower, especially on mobile devices.

PEM (Privacy-Enhanced Mail) is a Base64-encoded format with header and footer lines (e.g., -----BEGIN PUBLIC KEY-----). It's the most widely used format for storing and exchanging cryptographic keys. PEM files use the .pem or .key extension and are compatible with OpenSSL, SSH, and most server software.

JWK (JSON Web Key) is a JSON-based format defined by RFC 7517. It represents cryptographic keys as JSON objects, making them easy to use in web applications, JWT signing, and OAuth/OIDC flows. JWK is the native format for the Web Crypto API and is ideal for browser-based applications.

Yes. This tool uses the Web Crypto API (window.crypto.subtle), which provides cryptographically secure pseudo-random number generation (CSPRNG) backed by the operating system's entropy sources. The private key is generated in memory and never transmitted anywhere. However, for high-security applications, consider using a hardware security module (HSM) or air-gapped device.

A key fingerprint is a SHA-256 hash of the public key's DER-encoded SPKI structure. It serves as a compact, unique identifier for a key pair, commonly used for key verification (similar to SSH key fingerprints displayed as SHA256:xx:xx:...). You can share your public key fingerprint to allow others to verify they have the correct key.

P-256: Widely supported, 128-bit security level, very fast. Great for most applications.
P-384: 192-bit security level, used in higher-security environments and by some government agencies.
P-521: Highest security margin (256-bit+), but slower and less widely supported. Use only if you specifically need this level.

Yes. You can use the generated RSA or EC keys to create a Certificate Signing Request (CSR) for SSL/TLS certificates. Most Certificate Authorities accept both RSA (2048-bit minimum) and EC (P-256 minimum) keys. The PEM-formatted private key can be used directly with OpenSSL, certbot, or your hosting control panel to generate CSRs and install certificates.