JWT Tokens Explained: Authentication Made Simple

What is a JWT?

JSON Web Token (JWT) is an open standard for securely transmitting information between parties as a JSON object. JWTs are commonly used for authentication and information exchange.

JWT Structure

A JWT consists of three parts separated by dots: xxxxx.yyyyy.zzzzz

• Header: Token type (JWT) and signing algorithm
• Payload: Claims about the user and additional data
• Signature: Verifies the token hasn't been tampered with

How JWT Authentication Works

1. User logs in with credentials
2. Server validates and creates a JWT
3. JWT is sent to the client
4. Client includes JWT in subsequent request headers
5. Server validates the JWT signature and grants access

Security Best Practices

• Use HTTPS to prevent token interception
• Set short expiration times (15 minutes to 1 hour)
• Use refresh tokens for long sessions
• Store tokens securely (httpOnly cookies preferred)

Conclusion

JWTs provide a powerful solution for authentication in modern web applications. Use our free JWT decoder to inspect and validate tokens.