jwudtool version # Output: jwudtool 0.2.0 | Command | Purpose | |---------|---------| | decode | Decode header + payload without verifying signature | | verify | Check signature using a secret or public key | | forge | Create a new token from an existing one (change claims) | | fuzz | Test token against common attacks | Tutorial: Decode a JWT Given this sample token:
PAYLOAD:
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c Run: jwudtool tutorial
go install github.com/youruser/jwudtool@latest Got a feature request or found a bug? Open an issue on GitHub .
Learn how to decode, verify, and debug JSON Web Tokens using jwudtool. Perfect for developers and security testers. Introduction JSON Web Tokens (JWTs) are everywhere — from authentication flows to API authorization. But if you’ve ever tried to manually decode a JWT or debug a signature mismatch, you know it can get messy fast. jwudtool version # Output: jwudtool 0
Enter — a lightweight, command-line utility designed to simplify JWT inspection, manipulation, and testing.
💡 Tip: Use --pretty for colorized output. If you have the secret key ( mysecret ): Perfect for developers and security testers
"alg": "HS256", "typ": "JWT"
"sub": "1234567890", "name": "John Doe", "iat": 1516239022
✓ Signature valid If invalid:
jwudtool verify --secret mysecret <token> Expected output: