A 460 error is a custom status code returned by Amazon Web Services (AWS) Application Load Balancers (ALB).
It indicates that the client (the web browser, mobile application, or API caller) closed the network connection before the load balancer could finish receiving the response from the target backend server and forward it back.
Determining why
When an AWS load balancer handles a web request, it establishes a timer. If the user navigates away, clicks “Cancel” or “Stop” in their browser, closes the browser tab, or experiences a local network disconnection before the backend finished computing the answer, the ALB logs a 460 error.
Steps you can take
- Wait for requests to complete - If you are performing a lengthy action (like generating a large PDF or processing a report), keep the tab open and avoid refreshing prematurely.
- If you are the website owner or cloud architect:
- Increase client timeout settings - Check if client-side timeout settings in mobile apps or frontend JavaScript fetch calls are shorter than your backend’s processing time.
- Optimize backend database queries - If requests take dozens of seconds to respond, visitors will naturally navigate away. Optimize database indexes or convert slow tasks into background jobs.
- Verify ALB idle timeout configurations - Review your AWS Application Load Balancer idle timeout attributes in the AWS EC2 Management Console.