2026-01-17

nginx status code 497

In nginx (at least version 1.24.0) an HTTP request sent to a port listening only for HTTPS connections results in a nginx-specific 497 status code. The client is then presented with a 400 Bad Request. The plain HTTP request was sent to HTTPS port. To silently close these connections, configure nginx to return 444 on 497.

server {
  listen 443 ssl;
  ...
  error_page 497 =444 /;
}