JWT Key Generator
Generate HMAC secrets, RSA key pairs, and ECDSA key pairs for JWT signing. PEM output. Free online — runs locally, no upload.
32 bytes (256 bits)
Recommended: 32+ bytes for HS256, 48+ for HS384, 64+ for HS512.
Usage by algorithm:
- HS256/384/512 — HMAC with shared secret (symmetric)
- RS256/384/512 — RSA signature (asymmetric, 2048+ bits)
- ES256 — ECDSA P-256 (asymmetric, fastest, smallest sig)
- ES384 — ECDSA P-384
- ES512 — ECDSA P-521
All keys are generated locally using the browser's native Web Crypto API. Nothing is sent to any server.