How To Redirect www to Non-www with Nginx on CentOS 7

To complete this tutorial, you first need:

• Superuser privileges (a user in the wheel group) on the server that is running Nginx. If you don’t already have that set up, follow this tutorial: Initial Server Setup with CentOS 7.
• Nginx installed and configured to serve your website. Follow this tutorial to do that: How to Install Nginx on CentOS 7.
• A registered domain name. If you don’t have one yet, you can get a free one from Freenom. You may use whatever DNS provider you like (including your registrar) to host your domain’s records—just make sure to point your registrar to your provider’s nameservers. If you opt to use DigitalOcean DNS, this article from our documentation shows how to do that.

Let’s get started by configuring your DNS records.

First, you need to point both www.my-website.com and my-website.com to your server running Nginx. (The rest of the tutorial assumes your domain is my-website.com. Replace that with your own domain wherever you see it below.) You will do this by creating a DNS A record for each name that points to your Nginx server’s IP address.

Open your DNS provider’s web console. This tutorial uses DigitalOcean DNS.

In the Add a domain form, enter your registered domain name in the text field and click Add Domain. This will bring up the new domain’s page, where you can view, add, and delete records for the domain.

Under Create new record, type “@” in the HOSTNAME text field. This is a special character that indicates you are adding a record for the root domain name, a record for just plain my-website.com. In the WILL DIRECT TO text field, enter the public IPv4 address of your server, and click Create Record. (No need to change the TTL.)

For your second DNS record, you could use a CNAME record instead of an A record. A CNAME record is an alias that points to another name instead of an IP address. You could create a CNAME that directs www.my-website.com to my-website.com, and any HTTP request for the www subdomain would find its way to your server since you just created the A record for the root domain. But to keep things simple, just create another A record like the first one, entering “www” in the HOSTNAME field and the server’s public IP address in the WILL DIRECT TO field.

When you have created both records, it should look something like this:

With the two records in place, web requests for both my-website.com and www.my-website.com should reach your Nginx server. Now let’s configure the server.

As stated in the Prerequisites, you should already have your website configured in Nginx. It does not matter whether the site’s server block appears in the main /etc/nginx/nginx.conf file or in its own file. The important thing is that you have some server block configured with the server_name directive set to my-website.com and/or www.my-website.com. Whether your server_name contains one or both names, now is the time to decide which name you would like to be the one and only name to host the site.

Open the file that contains your website configuration (e.g., /etc/nginx/conf.d/my-website.com.conf) in vi or your favorite editor (yum install nano, if you prefer) and find the server_name directive:

sudo vi /etc/nginx/conf.d/my-website.com.conf

server {
    . . .
    server_name my-website.com www.my-website.com
    . . .
}

If you want to redirect www.my-website.com to my-website.com, remove www.my-website.com from the server_name line, and save and exit the file. (If you want to redirect my-website.com to www.my-website.com, remove my-website.com instead.)

Then, create a new Nginx configuration file called /etc/nginx/conf.d/www.my-website.com.conf (or /etc/nginx/conf.d/my-website.com.conf, if that is the name you are redirecting). Name the file whatever you like, but as with all Nginx configuration files, the file name must end in .conf:

sudo vi /etc/nginx/conf.d/www.my-website.com.conf

Add the following server block to the file, replacing my-website.com with your own domain name:

server {
    server_name www.my-website.com;
    return 301 $scheme://my-website.com$request_uri;
}

If you are redirecting my-website.com to the www subdomain instead, put my-website.com only in the server_name, and www.my-website.com in the URL on the next line.

Save and exit when you are finished.

This configures Nginx to send a 301 redirect back to any clients requesting www.my-website.com, and directs them to visit my-website.com instead. The redirect preserves the request URI, so that a request to http://www.my-website.com/login.php will be redirected to http://my-website.com/login.php.

Before applying the changes, check that your Nginx configuration is error free:

sudo nginx -t

Unless you made a syntax error (e.g., you forgot a semicolon), the configuration should be OK.

Output
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

Now restart Nginx to apply the new redirect rule:

sudo systemctl restart nginx

Before visiting www.my-website.com in your browser, make a request using curl on either your server or your local machine (if curl is installed locally):

curl -IL http://www.my-website.com

The -I flag tells curl to show only the headers from the server response. The -L flag tells curl to obey any redirects from the server by automatically making a second request, this time to the URL given in the Location header (just as a web browser would do). Since you have configured the 301 redirect, curl should make two requests, and you should see just the headers of the two responses:

Output
HTTP/1.1 301 Moved Permanently
Server: nginx/1.20.1
Date: Thu, 08 Dec 2022 19:24:44 GMT
Content-Type: text/html
Content-Length: 169
Connection: keep-alive
Location: http://my-website.com

HTTP/1.1 200 OK
Server: nginx/1.20.1
Date: Thu, 08 Dec 2022 19:24:44 GMT
Content-Type: text/html
Content-Length: 57
Last-Modified: Thu, 01 Dec 2022 22:10:57 GMT
Connection: keep-alive
ETag: "63892671-39"
Accept-Ranges: bytes

In the 301 (Moved Permanently) response to the original request to http://www.my-website.com, notice the last header: Location: http://my-website.com. The second response is from curl’s followup request to http://my-website.com, and if your website is healthy, the server should have responded with 200 (OK).

Finally, visit http://www.my-website.com in your web browser. Blink, and you’ll miss the redirect. Your website should appear as usual, but look again in your address bar and notice that the “www” is missing from the URL. Most users will never notice this, and so they will have the same experience as if they had requested http://my-website.com.

In this tutorial, you added two DNS records for your website and configured Nginx to redirect a secondary domain to your preferred domain. Now your website is reachable via both domains. Maybe it already was before you read this tutorial; perhaps you were serving it directly from both domain names. But with just four more lines of Nginx configuration, you have improved your website’s standing in the eyes of the search engines—and thereby exposed it to more users across the internet.

Want some further reading on how Nginx decides which server block will handle a given request? Check out this guide: Understanding Nginx Server and Location Block Selection Algorithms.