JWT Encoder
Build a demo JWT from header and payload JSON in your browser.
Tool workspace
Learning/debug only — not for production auth. Secret stays in your browser.
Builds a demo JWT locally. Blank secret → unsigned (alg: none). With secret → local HS256. Not for production authentication.
How it works
Enter header and payload JSON. Leave the secret blank for an unsigned token (alg: none). Provide a secret to sign locally with HS256.
This is for learning and debugging — not production authentication. Secrets never leave your browser.
Empty fields clear the result when all inputs are blank.
This is for learning and debugging — not production authentication. Secrets never leave your browser.
Empty fields clear the result when all inputs are blank.
Examples
- Header + payload, no secret → unsigned JWT ending with a trailing dot
- With secret → HS256-signed JWT
Privacy
Privacy: this tool builds JWTs locally in your browser. We do not log or store secrets or tokens. Login is not required.
FAQ
Is this safe for production auth?
No. Use a proper identity provider and key management in production.
Is my secret uploaded?
No. Signing runs entirely in your browser.
Do I need an account?
No. All published tools work for guests without login.