What causes "409 Conflict" in nginx/nginx?

409 Conflict

Error message

409 Conflict

What it means

Error "409 Conflict" thrown in nginx/nginx.

Source

Thrown at src/http/ngx_http_special_response.c:172


static char ngx_http_error_407_page[] =
"<html>" CRLF
"<head><title>407 Proxy Authentication Required</title></head>" CRLF
"<body>" CRLF
"<center><h1>407 Proxy Authentication Required</h1></center>" CRLF
;


static char ngx_http_error_408_page[] =
"<html>" CRLF
"<head><title>408 Request Time-out</title></head>" CRLF
"<body>" CRLF
"<center><h1>408 Request Time-out</h1></center>" CRLF
;


static char ngx_http_error_409_page[] =
"<html>" CRLF
"<head><title>409 Conflict</title></head>" CRLF
"<body>" CRLF
"<center><h1>409 Conflict</h1></center>" CRLF
;


static char ngx_http_error_410_page[] =
"<html>" CRLF
"<head><title>410 Gone</title></head>" CRLF
"<body>" CRLF
"<center><h1>410 Gone</h1></center>" CRLF
;


static char ngx_http_error_411_page[] =
"<html>" CRLF
"<head><title>411 Length Required</title></head>" CRLF

View on GitHub (pinned to 3f6f7824d4)

When it happens

Trigger: Thrown at src/http/ngx_http_special_response.c:172 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of nginx/nginx@3f6f7824d4 (2026-08-22). Data as JSON: /api/errors/dfac0d4e16a21103. Report an issue: GitHub.