kitzos

JWT Decoder

Decode and inspect JSON Web Tokens. View header, payload, and signature instantly in your browser. No data leaves your device.

Runs locally — nothing is uploaded

How to use

  1. 1

    Paste your JWT

    Paste a JSON Web Token into the input field. The tool decodes header and payload instantly as you type.

  2. 2

    Inspect claims

    View formatted JSON for the header and payload. Time claims like exp, iat, and nbf show human-readable dates.

  3. 3

    Copy sections

    Use Copy header or Copy payload to grab decoded JSON. The signature is shown as raw text only.

Frequently Asked Questions

No. It only decodes the header and payload locally in your browser. Your token is never sent to a server.