What Is a 499 Status Code?

A 499 status code — officially logged as “499 Client Closed Request” — is a non-standard HTTP code used by the nginx web server. It indicates that the client closed the connection before the server could send a response.

Common causes include:

• User cancels a request
• User navigates away before the page fully loads
• Misconfigured server settings
• Network issues that disrupt the connection between client and server

499 status code example

A 499 status code is not an officially recognized HTTP status code, but it is sometimes used by servers to indicate that a client has closed the connection without receiving a response. Here’s an example of a request and response:

Request

GET /index.html HTTP/1.1
Host: example.com

Response

HTTP/1.1 499 Client Closed Request
Server: nginx/1.19.6

Why Does a 499 Error Happen?

The HTTP 499 error is specific to the nginx web server, and it occurs when the client closes the connection before the server can send a response. There are a number of reasons why this could happen, including:

Network issues

If there is a problem with the network connection between the client and server, such as a dropped connection or high latency, the connection may be lost before the server can respond.

Client-side issues

If the client navigates away from the page before it fully loads, or cancels the request before the server can respond, the connection may be terminated before a response is received.

Server-side issues

If the servers is experiencing issues, such as a high load or a misconfiguration, it may be unable to respond to the client’s request in a timely manner.

Firewall or security software

If there is a firewall or security software in place that is blocking the connection or interfering with the communication between the client and server, the connection may be lost.

Misconfigured server

If the server is misconfigured, it may not be able to properly handle requests and may result in a 499 error.

Server-side timeout

The server may have a configuration that sets a timeout period for the response, and if it exceeds the limit, it may close the connection and result in a 499 error.

These are just a few examples of what could cause an HTTP 499 error. In order to determine the specific cause of the error, it may be necessary to investigate further using server logs or other troubleshooting methods.

How to Troubleshoot a 499 Status Code Error

Since the HTTP 499 error is not a standard HTTP status code, it can be tricky to troubleshoot. However, there are a few general steps that you can take to try to identify and resolve the issue:

• Check the server logs

If you have access to the server logs, check to see if there are any entries that correspond to the time that the HTTP 499 error occurred. This may provide clues as to what caused the error.

• Check the network connection

Verify that the network connection between the client and server is stable and reliable. Check for any network issues, such as dropped packets or high latency, which could cause the connection to be lost.

• Check the browser cache

Clear the browser cache and cookies to ensure that the error is not caused by a cached resource or cookie.

• Disable browser extensions

Disable any browser extensions that could be interfering with the connection, such as ad blockers or security software.

• Try a different browser or device

If the error persists, try accessing the site from a different browser or device to see if the issue is specific to the current configuration.

Does a 499 status code affect SEO?

A 499 status code doesn’t directly affect SEO since it’s not an official HTTP code. However, if it occurs frequently, it may impact crawl efficiency or user experience, leading to:

• Interrupted crawls from search bots
• Incomplete content rendering
• Higher bounce rate

If 499s appear often in server logs, investigate and address the underlying performance or timeout issues to maintain healthy crawl and UX performance.

408 vs 499 vs 504: Key Differences

Return to List of HTTP Status Codes