Redirect non-www and www URLs on Nginx

Introduction

When hosting a website, it's essential to ensure consistent URL structure for SEO benefits and user experience. A common practice is to redirect all traffic to either the www version (e.g., www.example.com) or the non-www version (e.g., example.com). You may run a website on the www or non-www address as a personal preference, but to prevent redundant hostnames it's recommended to choose one style and be consistent throughout your site. Whichever address you choose, you should make a permanent HTTP 301 redirect from the other address to prevent Google Analytics from logging it as a redundant hostname. This helps avoid duplicate content issues and provides a unified domain experience for your visitors.

This article explains how to redirect non-www and www URLs on Nginx by configuring it to redirect a non-www URL to the www address, or vice-versa.

Prerequisites

• You have a Vultr Linux instance running Nginx.
• You have a domain name such as example.com whose DNS A records for "@" and "www" are pointing to the IP address of the Vultr instance.

Nginx Hosting a Single Domain

How to Redirect non-www to www on Nginx

1. Locate your virtual host configuration file, which is typically located in /etc/nginx/sites-available.

2. Add an new server block at the top, above the existing server block, like:

    server {
        listen 80;
        server_name example.com;
        return 301 $scheme://www.example.com$request_uri;
    }

   This directive tells Nginx to send any request for http://example.com to http://www.example.com with HTTP redirect code 301.

3. Restart Nginx to apply the change. Ubuntu or Debian systems use the command:

    $ sudo systemctl restart nginx

How to Redirect www to non-www on Nginx

1. Locate your virtual host configuration file, which is typically located in /etc/nginx/sites-available.

2. Add an new server block at the top, above the existing server block, like:

    server {
        listen 80;
        server_name www.example.com;
        return 301 $scheme://example.com$request_uri;
    }

   This directive tells Nginx to send any request for http://www.example.com to http://example.com with HTTP redirect code 301.

3. Restart Nginx to apply the change. Ubuntu or Debian systems use the command:

    $ sudo systemctl restart nginx

Nginx Hosting Multiple Domains

If your Nginx server is hosting multiple domains, use this method to match all domain names.

To redirect the non-www URL to the www address for all domains, add this snippet inside the http directive in your nginx.conf file, which is usually located in /etc/nginx.

server {
    server_name "~^(?!www\.).*" ;
    return 301 $scheme://www.$host$request_uri;
}

Or, to redirect the www URL to the non-www address for all domains, add this snippet inside the http directive in your nginx.conf file, which is usually located in /etc/nginx.

server {
    server_name "~^www\.(.*)$" ;
    return 301 $scheme://$1$request_uri ;
}

Restart Nginx to apply the change. Ubuntu or Debian systems use the command:

$ sudo systemctl restart nginx