JWT vs Session-Based Authentication: Which Should You Use?

JWT vs Session Authentication

Choosing between JWT and session-based authentication depends on your application's requirements. Let's compare both approaches.

Session-Based Authentication

How It Works

User logs in with credentials

Server creates a session and stores it (database/memory)

Server sends session ID as a cookie

Client sends cookie with each request

Server validates session ID against stored sessions

Advantages

• Easy revocation: Simply delete the session
• Server control: Full control over active sessions
• Smaller payload: Only session ID transmitted
• Proven security: Well-understood security model

Disadvantages

• Stateful: Requires server-side storage
• Scaling challenges: Session sharing across servers
• CSRF vulnerability: Cookie-based sessions need CSRF protection

JWT Authentication

How It Works

User logs in with credentials

Server generates signed JWT

Client stores JWT

Client sends JWT with each request

Server validates JWT signature and claims

Advantages

• Stateless: No server-side storage needed
• Scalability: Works across multiple servers
• Cross-domain: Works across different domains
• Mobile-friendly: Easy to use in mobile apps

Disadvantages

• No instant revocation: Tokens valid until expiration
• Larger payload: Entire token transmitted each time
• Token storage security: XSS risks with localStorage

When to Use Each

Choose Sessions When:

• You need instant logout/revocation
• You have a single-domain application
• You prefer simpler security model
• Server resources aren't a concern

Choose JWT When:

• Building microservices architecture
• Need cross-domain authentication
• Building mobile applications
• Implementing single sign-on (SSO)
• Scaling across multiple servers

Hybrid Approach

Many applications use both:

• Short-lived JWTs for API authentication
• Refresh tokens stored as sessions
• Best of both worlds: stateless requests with revocation capability

Conclusion

There's no one-size-fits-all answer. Consider your application's architecture, scale requirements, and security needs when making your decision.