JWT Encoder / Decoder / Debugger - Free Online Tool

How to Use the JWT Tool

1

Paste a JWT

Enter your token in the JWT field and click Decode to inspect header and payload.

2

Verify Signature

Provide the shared secret and click Verify Signature to validate HS256 tokens.

3

Generate Token

Edit header/payload JSON and click Generate JWT to create a new token instantly.

What is a JWT?

A JSON Web Token is a compact token format commonly used for authentication and authorization. It consists of header, payload, and signature sections separated by dots.

How This JWT Debugger Helps

This tool helps you inspect token claims, verify HS256 signatures with your secret, and generate new tokens from custom JSON payloads during development and troubleshooting.

Common JWT Use Cases

API Debugging

Inspect claims and expiration values while testing protected API endpoints.

Auth Troubleshooting

Quickly confirm whether invalid login state comes from payload or signature issues.

Local Development

Generate sample JWTs for development and QA without using external tools.

Client-side Validation

Decode tokens directly in the browser without sending token contents to a server.

Frequently Asked Questions

No. Encoding, decoding, and verification are performed in your browser.

This tool currently verifies HS256 signatures.

Yes. If no secret is provided, the generated token is created without a signature.

No. Decoding only parses data. Use Verify Signature to validate token integrity.