JWT Decoder

How to Use:

• Paste a JWT token in the input field
• View the decoded header, payload, and signature
• Copy individual sections or all data
• Use the sample token to test the tool

JWT Structure:

• Header: Contains algorithm and token type
• Payload: Contains claims and data
• Signature: Used to verify token integrity
• All parts are Base64 encoded

What is a JWT token?

JWT (JSON Web Token) is a compact, URL-safe token format used for securely transmitting information between parties. It consists of three parts: header, payload, and signature.

Is this tool secure?

Yes! All JWT decoding happens in your browser. No tokens are sent to our servers, so your sensitive authentication data remains completely private.

Can I verify JWT signatures?

This tool only decodes JWT tokens. To verify signatures, you need the secret key and a proper JWT library. This tool is for inspection and debugging purposes.

What if the JWT is invalid?

The tool will show an error message if the JWT format is invalid or if decoding fails. Check that the token has three parts separated by dots.