JWTs are compact URL-safe strings used in Authorization headers, callbacks and test fixtures. This tool follows the JWS compact form: base64url header, base64url payload and a signature segment separated by dots. Use it as a development helper, not as production key management.
Générateur JWT gratuit
Fonctionne entièrement dans votre navigateur : aucun envoi, aucune inscription.
Use this for local testing. Do not paste production secrets into tools you do not control.
Que fait un générateur JWT ?
Un générateur JWT crée un JSON Web Token compact à partir d’un en-tête, de claims et d’un choix de signature. Cet outil génère des tokens HS256 avec Web Crypto dans le navigateur ou des tokens non signés pour le débogage, sans envoyer le JSON ni le secret à un serveur.
Comment l’utiliser
- 1Edit the header. Keep typ as JWT and choose HS256 or none.
- 2Add payload claims. Write a JSON object with sub, iat, exp or custom claims.
- 3Enter a clé secrète. For HS256, use only throwaway development values.
- 4Copy the token. Copy the generated compact JWT from the output box.
Pour qui
- API testing with a local HS256 bearer token.
- Claim debugging for iat, exp, sub and custom fields.
- Webhook sandboxing when an endpoint expects a JWT-shaped value.
- Documentation examples with non-sensitive sample claims.
Questions fréquentes
Is Générateur JWT free?
Yes. You can use this JWT generator without sign-up, account or usage limit.
Are my claims or secrets uploaded?
No. The JSON and HS256 secret are processed in the browser. For real systems, keep production signing keys in your own server or key-management environment.
Can I use this for production authentication?
Use it for local testing and examples. Production authentication also needs issuer checks, audience checks, expiry validation, replay controls, key rotation and secure storage.
Which algorithms are supported?
This version supports HS256 and the none algorithm for unsigned debugging tokens. It does not sign RS256, ES256 or private-key JWTs.
What is the none algorithm?
The none algorithm creates an unsigned JWT with an empty signature segment. It is useful only for debugging when a test system explicitly accepts it.
Why does the header alg change?
The selected algorithm button controls the real output, so the generator rewrites alg to HS256 or none to match the token it creates.