Free JWT decoder — decode and inspect JSON Web Token header, payload, and signature without verification.
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The QuickToolz JWT Decoder decodes any JSON Web Token (JWT) and shows the header, payload, and signature in human-readable form. Paste a token to inspect claims like iss, sub, aud, exp, iat, and any custom fields. Decoding runs entirely client-side — your token never leaves your browser.
A JWT has three parts separated by .: header.payload.signature. Each part is Base64URL-encoded. The header declares the signing algorithm; the payload contains claims; the signature is computed from header + payload + secret.
Decoding a JWT does NOT prove it’s authentic. Verification requires the issuer’s secret (HMAC) or public key (RSA/EC). Never trust a JWT’s claims without verifying its signature on your backend.
Everything you need, nothing you don’t. Built for speed and simplicity.
HS256, HS512, RS256, ES256, EdDSA — any standard JWT.
iat, exp, nbf shown in local time with expiry countdown.
Decoded locally in your browser — tokens never leave your device.
Everything you need, nothing you don’t. Built for speed and simplicity.
Drop in the full xxx.yyy.zzz token string.
Got questions? We’ve got answers. Common questions about JWT Decoder.
Clear warning that decoding ≠ verification.
Header, payload, and signature appear instantly, color-highlighted.
The exp claim is converted to a human-readable date and time-until-expiry.
JWT Decoder
Decodes header, payload, and signature. Verification is not performed.
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