How to Automatically Extend JWT Expiration Without Compromising Security

Introduction: The JWT Expiration Challenge

JSON Web Tokens (JWT) are widely used for stateless authentication in REST APIs. However, their fixed expiration time presents a dilemma: frequent reauthentication harms user experience, while long-lived tokens increase security risks. This post explores practical solutions to automatically extend JWT expiration without compromising security.

Why Extending JWT Expiration Matters

• User Experience (UX): Users expect uninterrupted access; frequent logouts cause frustration.
• Security: Long-lived tokens are vulnerable to hijacking, while short-lived tokens require renewal mechanisms.
• Stateless vs. Stateful: JWTs are stateless by design, but automatic renewal often requires server-side checks.

Solution 1: Refresh Tokens

How It Works:

1. Issue a short-lived access token (e.g., 15 minutes) and a long-lived refresh token (e.g., 7 days).
2. When the access token expires, the client sends the refresh token to obtain a new access token.
3. Store refresh tokens securely (HTTP-only cookies, mobile secure storage) and invalidate them on critical events (e.g., password reset).

Example Implementation:

// Generate tokens on login  
public AuthResponse login(User user) {  
  String accessToken = jwtUtils.generateToken(user, 15 * 60 * 1000); // 15 minutes  
  String refreshToken = jwtUtils.generateToken(user, 7 * 24 * 60 * 60 * 1000); // 7 days  
  return new AuthResponse(accessToken, refreshToken);  
}  

// Refresh endpoint  
@PostMapping("/refresh")  
public AuthResponse refresh(@RequestBody RefreshRequest request) {  
  if (jwtUtils.validateRefreshToken(request.refreshToken)) {  
    User user = getUserFromToken(request.refreshToken);  
    return new AuthResponse(jwtUtils.generateAccessToken(user), null);  
  }  
  throw new InvalidTokenException();  
}  

Pros & Cons

✅ Minimal server-side state
✅ Granular control over token revocation
❌ Requires secure storage for refresh tokens

Solution 2: Sliding Sessions with Short-Lived JWTs

How It Works:

1. Set a short expiration (e.g., 15 minutes) for the access token.
2. On every API request, check the token’s remaining validity.
3. If the token is near expiry, issue a new one transparently.

Backend Check:

// Middleware to auto-refresh token  
public void checkTokenExpiry(HttpServletRequest request, HttpServletResponse response) {  
  String token = parseJwt(request);  
  if (jwtUtils.isExpiringSoon(token)) {  
    String newToken = jwtUtils.renewToken(token);  
    response.setHeader("New-Access-Token", newToken);  
  }  
}  

Pros & Cons

✅ No refresh tokens needed
✅ Seamless UX with automatic renewal
❌ Requires client-side logic to update the new token

Solution 3: JWT Versioning

How It Works:

1. Add a jwt_version field to your user database.
2. Encode this version in the JWT payload.
3. Invalidate all tokens by incrementing the version (e.g., on password reset).

Database Example:

Token Validation:

if (user.getJwtVersion() != jwt.getVersion()) {  
  throw new ExpiredTokenException();  
}  

Pros & Cons

✅ Minimal server-side storage
✅ Easy bulk invalidation

Solution 4: Proactive Token Refresh (Frontend Libraries)

For JavaScript apps, libraries like jwt-autorefresh automate token renewal:

import autorefresh from 'jwt-autorefresh';  

autorefresh({  
  refresh: () => fetch('/refresh-token'),  
  leadSeconds: 60 // Refresh 60 seconds before expiry  
});  

Pros & Cons

✅ Zero manual intervention
✅ Built-in jitter to prevent client collisions

When to Avoid JWT for Prolonged Sessions

• High-Security Apps: Use stateful sessions with Redis for immediate revocation.
• Native Mobile Apps: Pair JWTs with device-specific refresh tokens (e.g., revoke by device ID).

Best Practices

1. Always Use HTTPS: Prevent token interception.
2. Set Realistic Expiry Times: 15 minutes for access tokens, 7 days for refresh tokens.
3. Monitor Token Usage: Detect anomalies (e.g., sudden geographic changes).

Conclusion

JWT expiration prolongation is achievable with refresh tokens, sliding sessions, or versioning. Choose based on your app’s security needs and infrastructure. For most web apps, refresh tokens strike the best balance between UX and security.

Keywords: JWT automatic prolongation, refresh token implementation, JWT expiration extension, sliding session JWT, JWT versioning, JWT security best practices, stateless authentication, JWT vs session tokens.

This guide ensures a smooth user experience while maintaining security—keeping users logged in safely! 🔑