API Security Lab
JWT Security Analysis
JSON Web Token Vulnerabilities & Forgery
Overall Progress0%
Educational Purpose Only — Practice only on systems you own or have explicit written permission to test.
Level 1:Token Anatomy
EasyA JWT consists of three parts: Header, Payload, and Signature. They are just Base64Url encoded JSON.
Objective
Decode the token to find the hidden "flag" claim in the payload.
Scenario
You captured a token from a user session. Decode it to see what information it contains.
JWT DebuggerAlgorithm: HS256