✗ Signature mismatch For RS256 tokens, use a public key:
"sub": "1234567890", "name": "John Doe", "iat": 1516239022
Enter — a lightweight, command-line utility designed to simplify JWT inspection, manipulation, and testing.
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 tutorial
go install github.com/youruser/jwudtool@latest Got a feature request or found a bug? Open an issue on GitHub .
"alg": "HS256", "typ": "JWT"
PAYLOAD:
HEADER:
💡 Tip: Use --pretty for colorized output. If you have the secret key ( mysecret ):
Mastering JWTs: A Step-by-Step Tutorial to jwudtool ✗ Signature mismatch For RS256 tokens, use a
✓ Signature valid If invalid:
jwudtool verify --secret mysecret <token> Expected output: