/codes /nginx/nginx-special-status-codes

nginx status codes 444, 499, 413 and 494-497

updated 2026-10-20

tool: nginx
versions: nginx 1.x
os: any

Besides the standard HTTP codes, nginx uses a few codes of its own. They mostly appear in the access log, not in responses: 444 sends nothing at all, and 499 is logged when the client disconnected before nginx could answer.

nginx-specific codes

Code	Meaning	What the client sees
444	return 444; closes the connection without sending a response	empty reply (curl exit 52)
494	request header too large (large_client_header_buffers)	400 Bad Request
495	client certificate verification failed	400 Bad Request
496	client did not send a required certificate	400 Bad Request
497	plain HTTP request sent to an HTTPS port	400 Bad Request
499	client closed the connection before the response	nothing (it already left)

The 494–497 codes can be caught with error_page 497 https://$host$request_uri; to redirect plain HTTP on the TLS port.

444, 413 and 499 on a real nginx

bash

mkdir -p logs temp
cat > slow.js <<'EOF'
const s = require("http").createServer((req, res) => setTimeout(() => res.end("late\n"), 2000));
s.listen(3911, "127.0.0.1");
setTimeout(() => process.exit(0), 5000);
EOF
cat > nginx.conf <<'EOF'
pid logs/nginx.pid;
events {}
http {
  log_format short '$request_method $uri $status';
  access_log logs/access.log short;
  client_max_body_size 1k;
  server {
    listen 127.0.0.1:3912;
    location /drop   { return 444; }
    location /upload { return 200 "stored\n"; }
    location /slow   { proxy_pass http://127.0.0.1:3911; }
  }
}
EOF
node slow.js &
nginx -p . -c nginx.conf -e logs/error.log &
sleep 1
curl -s http://127.0.0.1:3912/drop; echo "curl exit status: $?"
head -c 4096 /dev/zero | curl -s -o /dev/null -w 'upload 4 KiB: %{http_code}\n' --data-binary @- http://127.0.0.1:3912/upload
curl -s --max-time 1 http://127.0.0.1:3912/slow; echo "curl exit status: $?"
sleep 1
nginx -p . -c nginx.conf -e logs/error.log -s stop
echo "--- access.log"; cat logs/access.log

Output

curl exit status: 52
upload 4 KiB: 413
curl exit status: 28
--- access.log
GET /drop 444
POST /upload 413
GET /slow 499

413 Request Entity Too Large is a standard code (RFC 9110 calls it Content Too Large); nginx returns it when the body exceeds client_max_body_size, 1 MiB by default.

Sources

codes · httpHTTP status codes: 1xx to 5xx with meaning and common causesHTTP status codes explained: 200 and 204, the redirects 301 to 308, client errors 400 to 429 and server errors 500 to 504, each with its most common cause.cheat sheets · nginxnginx cheat sheet: commands, server blocks, locations and proxyingnginx cheat sheet: test and reload, logs, server blocks, location matching order, reverse proxy headers, HTTPS redirects, static files and caching headers.config · nginxnginx proxy_pass with and without a trailing slashproxy_pass http://app without a path forwards the full URI; with a path like http://app/ nginx replaces the matched location prefix. Real requests shown.

nginx-specific codes

444, 413 and 499 on a real nginx

Sources

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