How to set up WordPress behind a secure reverse proxy using NGINX

By Albin / 2020-01-27

After getting your SSL certificate and enabling HTTPS redirection in NGINX, WordPress will not work due to mixed content (HTTP and HTTPS) – you won’t be able to login.

To fix this:

1. Edit wp-config.php

Add this at the very start of your wp-config.php:

define('FORCE_SSL_ADMIN', true);
if ($_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https')
 $_SERVER['HTTPS']='on';

Then, at the end of the file, add the following (replacing website.com with your actual domain):

define('WP_HOME','https://website.com');
define('WP_SITEURL','https://website.com');

2. Edit your NGINX reverse proxy config

In the site’s location block on your reverse proxy, add:

proxy_set_header X-Forwarded-Proto https;

Now it should be working!

You should probably also install the plugin Really Simple SSL for its mixed content fixer.