Free Online JWT Generator

1. Pick the algorithm (HS256 is the standard default).
2. Edit the header JSON if you need extra fields beyond alg and typ.
3. Edit the payload JSON to set your claims — sub, exp, iat, iss, plus anything custom.
4. Enter the signing secret, click Sign token, and copy the resulting JWT.

A JSON Web Token (RFC 7519) is three Base64Url-encoded segments — header, payload and signature — joined with dots. The header (JOSE header per RFC 7515) names the signing algorithm; the payload carries registered claims like `sub`, `exp`, `iat`, `iss`, `aud` plus any custom claims; the signature binds them together so a server can verify the token came from a holder of the signing key without storing session state.

This generator signs with HMAC — the HS-family algorithms. HS256 is the most common choice: short tokens, fast verification, just one shared secret. HS384 and HS512 widen the MAC at a small CPU cost. For multi-party verification where the issuer alone should be able to forge tokens, switch to RS256 (RSA signature) or ES256 (ECDSA), which need an asymmetric key pair this tool does not generate.

Tokens are signed locally and not stored. Never put real production secrets inside the payload — it is Base64-encoded, not encrypted, and anyone holding the token can read every claim.