JWT vs Session-based Auth
Differences, use cases, and when to use each
JWTs are self-contained tokens that carry user data (stateless). Session-based auth stores data on the server with only an ID in the cookie (stateful). JWTs scale better; sessions offer easier revocation.
Quick Comparison
| Feature | JWT | Session-based Auth |
|---|---|---|
| State Storage | Client-side (token) | Server-side (session store) |
| Scalability | Excellent (no server state) | Requires shared session store |
| Revocation | Difficult (needs blacklist) | Instant (delete session) |
| Size | Larger (carries claims) | Small (session ID only) |
| Server Lookup | Not needed (self-contained) | Required per request |
When to Use Each
When to Use JWT
Use JWTs for stateless APIs, microservice architectures, and mobile apps where server-side session storage is impractical or where services need to independently verify identity.
When to Use Session-based Auth
Use session-based auth for traditional web apps where you need instant revocation capability, smaller cookies, and don't need to scale across multiple services.
Pros & Cons
JWT
Session-based Auth
Verdict
Sessions for traditional web apps needing simple revocation. JWTs for APIs, SPAs, and microservices where statelessness and cross-service auth matter. Many apps use both: short-lived JWTs with server-side refresh tokens.