Décodeur JWT
Décodeur JWT gratuit. Décodez les jetons Web JSON pour inspecter l'en-tête et le contenu. Les jetons ne quittent jamais votre navigateur. Pour OAuth, débogage d'authentification, intégration API.
Runs in your browserUpdated Apr 26, 2026
JWT Token
Header
Payload
Questions fréquentes
›Does this verify the JWT signature?
No — the decoder shows header and payload only. Signature verification requires the issuer's secret or public key, which we never receive.
›Is my token sent to your servers?
Never. Decoding runs entirely in your browser — tokens stay on your device.
›What algorithms are supported?
Any JWT can be decoded (HS256, RS256, ES256, etc.) — decoding is algorithm-agnostic. Verification is the algorithm-specific step.
›What does each part of a JWT contain?
Header: algorithm and token type. Payload: claims (sub, iat, exp, custom data). Signature: HMAC or signature over header.payload using a secret/key.
›Is the decoder free?
Yes — fully free, no signup.