Question 1

What is a JWT Token?

Accepted Answer

JWT (JSON Web Token) is an open standard (RFC 7519) for securely transmitting information between parties. It consists of three parts: Header, Payload, and Signature, separated by dots.

Question 2

Is JWT secure?

Accepted Answer

JWT itself is secure, but improper use can introduce risks. Key security practices include: always use HTTPS, set reasonable expiration times, never store sensitive data in the payload, use strong signature algorithms (e.g. RS256), and always verify signatures.

Question 3

What's the difference between JWT and Session?

Accepted Answer

JWT is stateless — the server doesn't store session info, making it ideal for distributed systems. Sessions are stateful — the server stores session data, making them easier to control and revoke. JWT is great for APIs and microservices, while sessions suit traditional web apps.

🔐 JWTDecoder

📋 JWT Structure

📄 DecodeResult

Header（Header）

Payload（Payload）

📖 Payload Field Descriptions

🛡️ Security Check