// http 5xx · server error
HTTP 504 Gateway Timeout
An upstream server didn't respond in time.
What HTTP 504 Gateway Timeout means
504 Gateway Timeout means a proxy or gateway didn't get a response from an upstream server in time. Like 502 it's about the upstream, but here the upstream was too slow rather than broken.
Which category is it?
504 is a 5xx code — Server error. 5xx means the server failed to fulfil an apparently valid request. It's the server's responsibility, not the caller's.
Common causes
- An upstream service responding too slowly
- A long-running query or request exceeding the timeout
- Network issues between proxy and origin
How to fix it
- Speed up or optimise the slow upstream operation
- Raise the gateway timeout if the work is legitimately long
- Check connectivity between the proxy and origin