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

JWT vs Sessions: Which Should You Use?

Both approaches have their place. Understanding the tradeoffs helps you make the right choice.

Session-Based Authentication

Client                    Server
  |                         |
  |-- Login credentials --> |
  |                         | Create session in DB
  |<-- Session cookie ----  |
  |                         |
  |-- Request + cookie -->  |
  |                         | Lookup session in DB
  |<-- Response ----------  |

Pros:

• Easy to revoke (delete from DB)
• Session data stays on server
• Battle-tested approach

Cons:

• Requires database lookup per request
• Harder to scale horizontally
• Sticky sessions may be needed

JWT Authentication

Client                    Server
  |                         |
  |-- Login credentials --> |
  |                         | Create & sign JWT
  |<-- JWT token ---------  |
  |                         |
  |-- Request + JWT ----->  |
  |                         | Verify signature only
  |<-- Response ----------  |

Pros:

• Stateless - no DB lookup needed
• Scales horizontally easily
• Works across microservices
• Good for mobile/SPAs

Cons:

• Can't easily revoke tokens
• Token size larger than session ID
• Complexity in refresh token handling

When to Use Sessions

• Traditional server-rendered apps
• When you need instant revocation
• Simpler applications
• When you already have session infrastructure

When to Use JWTs

• Microservices architecture
• Mobile applications
• Single Page Applications (SPAs)
• Cross-domain authentication
• When horizontal scaling is important

Hybrid Approach

Many apps use both:

// Short-lived JWT for API access (15 min)
// Server-side session for refresh tokens
// On API request: Validate JWT (no DB)
// On token refresh: Check session (DB lookup)
// On logout: Invalidate session (blocks refresh)