JWT Debugger
Decode and inspect JWT tokens (header/payload)
About
This JWT debugger allows you to decode and inspect the header and payload of JSON Web Tokens. It's useful for debugging JWT issues, understanding token structure, and verifying claims. Note that this tool does not verify signatures, only decodes the token contents. ### How to Use 1. Enter or paste your data in the input field. 2. Adjust any available settings or options. 3. Click the action button to process. 4. Copy or download the result.
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How to Use
This JWT debugger allows you to decode and inspect the header and payload of JSON Web Tokens. It's useful for debugging JWT issues, understanding token structure, and verifying claims. Note that this tool does not verify signatures, only decodes the token contents.
JWT Token
What is a JWT?
JSON Web Token (JWT) is an open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object.
A JWT token consists of three parts separated by dots:
- Header: Contains metadata about the token, such as the signing algorithm
- Payload: Contains the claims (data) stored in the token
- Signature: Used to verify that the token hasn't been tampered with
Examples
Input
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c
Output
Header: {"alg":"HS256","typ":"JWT"}, Payload: {"sub":"1234567890","name":"John Doe","iat":1516239022}JWT decoding example
FAQ
What is a JWT token?
JWT (JSON Web Token) is a compact, URL-safe means of representing claims to be transferred between two parties.
Why doesn't this tool verify signatures?
Signature verification requires the secret key, which should never be exposed in a client-side tool.
Is this tool free?
Yes, this tool is completely free to use.
Is my data secure?
Yes, all processing is done in your browser. Your data is not sent to any server.
Does it work offline?
Yes, once the page is loaded, you can use the tool offline.