>Fafa Dev Tools

JWT Decoder

Decode and inspect JWT tokens instantly. Free online JWT decoder with header, payload, and expiration analysis.

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What is JWT Decoder?

JWT (JSON Web Token) is an open standard (RFC 7519) for securely transmitting information between parties as a JSON object. A JWT consists of three parts separated by dots: header.payload.signature. For example: eyJhbGciOiJIUzI1NiJ9.eyJzdWIiOiJ1c2VyMSJ9.signature. JWTs are commonly used for authentication and authorization in web applications.

How to Use

  1. Paste your JWT token in the input area (it usually starts with eyJ)
  2. The tool automatically decodes the header and payload sections
  3. Check the expiration status — expired tokens are highlighted
  4. Common fields like sub (subject), iat (issued at), exp (expiration) are labeled

Examples

Decode a JWT

InputeyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ
OutputHeader: {"alg":"HS256","typ":"JWT"} | Payload: {"sub":"1234567890","name":"John Doe"}

Frequently Asked Questions

Is it safe to paste my JWT here?

Yes. All decoding happens in your browser. Your token never leaves your device. However, never share your JWT with others — it can grant access to your account.

Can this tool verify JWT signatures?

No. This tool only decodes the header and payload (which are just Base64-encoded JSON). Signature verification requires the secret key or public key, which should never be shared.

What's the difference between JWT, JWS, and JWE?

JWT is the token format. JWS (JSON Web Signature) is a signed JWT — the most common type. JWE (JSON Web Encryption) is an encrypted JWT where the payload is not readable without the decryption key.