FK
FreeAIKit

JWT Decoder

Decode JSON Web Tokens to inspect header, payload, and signature. Check expiration and claims. Free, instant, in-browser.

FAQ

What is a JWT?

A JSON Web Token (JWT) is a compact, URL-safe token format used for authentication and information exchange. It consists of three Base64-encoded parts separated by dots: header, payload, and signature.

Is it safe to paste my JWT here?

Yes! This tool runs entirely in your browser. Your JWT is never sent to any server. However, never share JWTs publicly as they may contain sensitive claims.

Can this tool verify JWT signatures?

This tool decodes and displays JWT contents but does not verify signatures, as that requires the secret key or public key which should remain on your server.

What are common JWT claims?

Common claims include: iss (issuer), sub (subject), aud (audience), exp (expiration), nbf (not before), iat (issued at), and jti (JWT ID). Custom claims can contain any application-specific data.

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