HTTP 408 Request Timeout

What It Means

The HTTP 408 Request Timeout status code indicates that the server did not receive a complete request from the client within the time it was prepared to wait. The server is closing the connection.

408 vs 504

408: Server waiting for client to send request
504: Server waiting for upstream server to respond

Common Causes

Slow client connection: Poor network conditions
Large request body: Uploading big files on slow connection
Client paused: Application stopped sending data mid-request
Network interruption: Packet loss or connectivity issues
Keep-alive timeout: Idle connection timed out

Example Response

HTTP/1.1 408 Request Timeout
Connection: close
Content-Type: text/html

<html>
<body>
  <h1>Request Timeout</h1>
  <p>The server timed out waiting for your request.</p>
</body>
</html>

Server Configuration

Nginx

# Client request timeout settings
http {
    client_header_timeout 60s;  # Time to receive headers
    client_body_timeout 60s;    # Time to receive body
    send_timeout 60s;           # Time between writes
    keepalive_timeout 75s;      # Idle connection timeout
}

Apache

# Timeout for client to send request
Timeout 60

# Keep-alive settings
KeepAliveTimeout 5

Client-Side Handling

async function fetchWithRetry(url, options, retries = 3) {
  for (let i = 0; i < retries; i++) {
    try {
      const response = await fetch(url, options);
      if (response.status === 408) {
        console.log('Request timeout, retrying...');
        continue;
      }
      return response;
    } catch (error) {
      if (i === retries - 1) throw error;
    }
  }
}

Debugging Tips

Check your network connection speed
Try smaller payloads to isolate the issue
Monitor request timing in browser DevTools
Check server timeout configuration
Look for network interruptions (VPN, proxy)

Prevention

Use chunked uploads for large files
Implement progress indicators for long uploads
Consider increasing timeout for slow endpoints
Add retry logic for transient failures