What does HTTP 504 mean?
A gateway did not receive a timely response from the upstream server.
Common causes and when you see it
Slow database queries or upstream services exceeding proxy timeouts.
How to fix or handle it
Optimise slow operations, raise proxy timeouts carefully and use background jobs for long tasks.
Test it yourself
Send a request with the online API tester, inspect the response with the HTTP header checker, or host an endpoint that returns 504 with the mock API generator to see how your app reacts.
Server errors hurt users and SEO. Monitor your endpoints so you know about 504 responses before your customers do.
HTTP 504 questions
A gateway did not receive a timely response from the upstream server.
Slow database queries or upstream services exceeding proxy timeouts.
Optimise slow operations, raise proxy timeouts carefully and use background jobs for long tasks.