JWT Decoder — Free Online Tool

Use JWT Decoder for free — decode json web tokens instantly. inspect headers, payload data, and expiration times safely. This tool runs 100% in your browser with zero server uploads. Part of ZeroApiTools, a collection of 65+ free developer tools. No signup, no API keys, no data collection. Works offline.

Welcome to the ultimate JWT Decoder, designed specifically for developers who need to quickly inspect JSON Web Tokens without compromising security. Parse tokens instantly right in your browser, completely offline and with zero server uploads required.

What does this JWT Decoder do?

A JWT (JSON Web Token) consists of three parts: a Header, a Payload, and a Signature. Our decoder parses the Base64Url encoded segments of your token, instantly revealing the human-readable JSON contents of the header and the payload (claims) so you can debug authentication issues.

How to decode your tokens

  1. Copy your JSON Web Token (usually starting with `eyJ...`) from your local storage, cookie, or authorization header.
  2. Paste the token into the input area provided above.
  3. The tool will immediately parse the token and display the decoded Header and Payload in a formatted, easy-to-read JSON structure.
  4. You can also view critical timestamps like `iat` (Issued At) and `exp` (Expiration Time) converted into readable dates.

Why use a local JWT Decoder?

JSON Web Tokens often contain sensitive user information, session data, or authorization scopes. Using an offline, browser-based decoder ensures that your proprietary application data and user identities remain strictly on your device.

100% Client-Side Processing

We prioritize your security. This decoder uses pure JavaScript to parse the token directly within your browser. We never log, store, or transmit your JWTs to any external server.