MARZ.tools

JWT Decoder

Decode JSON Web Tokens to inspect their header and payload.

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About this tool

Paste a JWT to instantly decode and view its header and payload as formatted JSON. This tool decodes only — it does not verify the signature.

How to use

  1. Paste a JWT string into the input box.
  2. The decoded header and payload appear as formatted JSON.
  3. Check expiry and claims directly in the output.

FAQ

Does this verify the token's signature?

No. This tool only decodes the header and payload for inspection — it does not verify signature validity, so never treat a decoded token as authenticated.

Is my token sent anywhere?

No, decoding happens entirely in your browser. Avoid pasting production secrets into any online tool regardless.

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