What it means
nginx logs 499 when the client closed the connection before the server sent a response. The client never sees this code.
Common causes
- User navigated away or cancelled the request
- Client timeout shorter than server processing time
- Load balancer health check timeout
How to fix it
As a client or visitor
Raise the client or load balancer timeout if requests are legitimately slow.
As the site or API owner
Speed up slow endpoints and look at upstream latency; consider proxy_ignore_client_abort for work that must complete.
Example response
HTTP/1.1
HTTP/1.1 499 Client Closed Request
Date: Tue, 07 Oct 2025 09:30:00 GMT
Server: nginx
Content-Length: 0Specification
Not in the IANA registry; used by nginx.
FAQ
› Is 499 an official status code?
No. It is an nginx logging code, not sent on the wire.
› Why do I see many 499s in nginx logs?
Clients or upstream load balancers are giving up first; compare their timeouts with your response times.