What does HTTP status code 504 mean?
The 504 Gateway Timeout status code indicates that a proxy server or gateway timed out waiting for a response from the backend application node.
When to use it in APIs
Generated by gateways when heavy queries, long-running processes, or external API dependencies block the execution thread beyond connection limits. A Proxy-Status header from the gateway says which wait expired, such as error=connection_timeout or error=http_response_timeout.
How it compares to other codes
- 502 Bad Gateway: Means the backend returned an invalid response quickly. 504 means the backend took too long to return anything.
