← All status codes4xx – Client Error

HTTP 499 – Client Closed Request

(NGINX) The client closed the connection before the server could finish sending a response.

Common use case

Very common for slow backend requests where an impatient client (or a frontend with an aggressive timeout) gives up and disconnects before NGINX finishes proxying the response.

History

An NGINX-specific extension, not part of any official HTTP specification.

Did you know?

It is one of the most frequently seen "error" codes in NGINX access logs that isn't actually an error on the server's part at all - the client simply left first.

Other 4xx codes

400Bad Request401Unauthorized402Payment Required403Forbidden404Not Found405Method Not Allowed406Not Acceptable407Proxy Authentication Required408Request Timeout409Conflict410Gone411Length Required412Precondition Failed413Content Too Large414URI Too Long415Unsupported Media Type416Range Not Satisfiable417Expectation Failed418I'm a teapot422Unprocessable Content425Too Early426Upgrade Required428Precondition Required429Too Many Requests430Shopify Security Rejection431Request Header Fields Too Large444No Response451Unavailable For Legal Reasons460Client Closed Connection463Malformed X-Forwarded-For Header464Incompatible Protocol Versions494Request Header Too Large495SSL Certificate Error496SSL Certificate Required497HTTP Request Sent To HTTPS Port