Gateway Timeout

Server perspective

Use 504 when acting as a gateway or proxy and the upstream server did not respond before your timeout expired.

When to use

• •Return 504 when a backend or origin takes too long and the intermediary times out waiting
• •Use it only when this server depends on an upstream response to finish the request

How to respond

• •Set and monitor realistic upstream deadlines, then log which dependency timed out and after how long
• •Return a clear timeout response instead of leaving the client hanging on an open connection

Headers to consider

• •No status-specific header is required; include request or trace metadata when it helps operators correlate the upstream timeout

Response body

• •A body is optional but helpful; explain that an upstream dependency timed out and include safe retry guidance when appropriate

Server-side pitfalls

• •Do not use 504 for client-to-server request timeouts; that is 408 Request Timeout
• •Do not use 504 for malformed upstream responses; that is 502 Bad Gateway

Examples