APITester| Status code | 524 |
|---|---|
| Status text | A Timeout Occurred |
| Category | 5xx Server Error |
| Response has body | Usually |
| Defined by | Cloudflare (not an IANA-registered code) |
What does 524 A Timeout Occurred mean?
Cloudflare connected to the origin server, but the origin took too long to send a response. It is numbered in the 5xx Server Error range but is not a registered HTTP status code, so the general meaning of that class is only a rough guide to it.
When do APIs return 524?
On sites behind Cloudflare, when a request runs longer than Cloudflare will wait, which by default is on the order of two minutes. The connection was fine; the application was slow. Long database queries, report generation, large exports and imports are typical.
How to fix a 524 A Timeout Occurred
Shorten the request. Move long work to a background job: accept the request, answer 202 with a status URL, and let the client poll. Check the origin for slow queries and exhausted worker pools. The wait can be extended on Cloudflare's Enterprise plan, and requests to a hostname that is not proxied through Cloudflare are not subject to it, which is a common arrangement for a slow internal endpoint.
Reproduce a 524 response
The fastest way to understand a status code is to trigger one and read the full response. Open the
API tester and send a request to https://httpbin.org/status/524 — you will
see the 524 status along with every response header the server sent. Comparing those headers against
a working request is often what reveals the cause.
That response only imitates the number, which is useful for checking how your own client, alerting or retry logic treats a 524. A real one comes from the software named in the table above, in the circumstances this page describes.
When you are debugging a real endpoint, check the response headers as carefully as the body, and confirm you are using the right HTTP method for the operation.
Related 5xx status codes
500 Internal Server Error
The server hit an unexpected condition and could not complete the request.
501 Not Implemented
The server does not support the functionality required to fulfil the request.
502 Bad Gateway
A server acting as a gateway or proxy received an invalid response from the upstream server.
503 Service Unavailable
The server is temporarily unable to handle the request.
504 Gateway Timeout
A gateway or proxy did not receive a timely response from the upstream server.
505 HTTP Version Not Supported
The server does not support the major HTTP version named in the request.
See also
- 504 Gateway Timeout — A gateway or proxy did not receive a timely response from the upstream server.
- 522 Connection Timed Out — Cloudflare tried to open a TCP connection to the origin server and got no answer in time.
References
- Cloudflare Docs: Error 524 — Cloudflare's own description of the cause and the checks to run.
- IANA: HTTP Status Code Registry — The official list of registered codes. This one is not on it.