Toolwise

JWT Decoder

Paste a JWT to instantly decode and inspect its header and payload claims.

How to use JWT Decoder

  1. 1Paste your JWT into the input.
  2. 2The decoded header and payload appear instantly as formatted JSON.
  3. 3Note: this tool does not verify the signature.

About JWT Decoder

A JSON Web Token (JWT) encodes a header, payload and signature as three Base64URL-encoded segments. This tool decodes the header and payload so you can inspect the claims inside — entirely in your browser, without sending your token anywhere.

Benefits

  • • Quickly inspect claims like expiry, issuer or subject without a backend call.
  • • Runs entirely client-side — your token is never transmitted anywhere.

Common mistakes

  • • Assuming a decoded JWT is verified — decoding only reveals the contents, it doesn't confirm the token's signature is valid.

Frequently Asked Questions

No, this tool only decodes and displays the header and payload. Signature verification requires the secret or public key and isn't performed here.

No, decoding happens entirely in your browser using JavaScript.

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