504 Gateway Timeout | HTTP Status Code

Explanation

The 504 (Gateway Timeout) status code indicates that the server, while acting as a gateway or proxy, did not receive a timely response from an upstream server it accessed in attempting to complete the request. This typically occurs when the upstream server is slow to respond or unresponsive, while the gateway or proxy has a configured timeout for how long it will wait.

This error is different from a 502 (Bad Gateway) error in that a 504 specifically indicates a timeout issue, whereas a 502 indicates that the upstream server's response was invalid or corrupted in some way.

Common causes for a 504 error include:
- Overloaded upstream servers
- Network congestion or latency issues
- Complex operations that take longer than the configured timeout
- Upstream server crashes or stalls during processing

Example Response

HTTP/1.1 504 Gateway Timeout
Content-Type: text/html

<html>
<head>
<title>Gateway Timeout</title>
</head>
<body>
<h1>Gateway Timeout</h1>
<p>The proxy server did not receive a timely response from the upstream server.</p>
</body>
</html>

Related Status Codes

500 500 Internal Server Error 502 502 Bad Gateway 503 503 Service Unavailable