How to Redirect Non-WWW to WWW in Nginx

To redirect non-www to www in nginx, create a server block for the non-www domain that uses a return 301 directive to send visitors to the www version. This ensures all traffic to example.com is permanently redirected to www.example.com.

Syntax

The basic syntax to redirect non-www to www in Nginx involves creating a server block for the non-www domain and using the return 301 directive to redirect to the www domain.

• server_name: Specifies the domain to match (non-www).
• return 301: Sends a permanent redirect status code.
• $scheme: Keeps the original request protocol (http or https).
• $host: The requested host name, replaced here with www domain.
• $request_uri: The full original request path and query string.

nginx

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

Example

This example shows a complete Nginx configuration that redirects all requests from example.com to www.example.com. It listens on port 80 and issues a permanent redirect preserving the original path and query.

nginx

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

server {
    listen 80;
    server_name www.example.com;

    location / {
        root /var/www/html;
        index index.html;
    }
}

Output

When a user visits http://example.com/page, the browser receives a 301 redirect to http://www.example.com/page.

Common Pitfalls

Common mistakes when redirecting non-www to www in Nginx include:

• Forgetting to specify the correct server_name for the non-www domain.
• Using rewrite instead of return 301, which is less efficient.
• Not preserving the original request URI, causing users to lose the requested page path.
• Missing the $scheme variable, which can cause protocol mismatches.

nginx

Wrong way:
server {
    listen 80;
    server_name example.com;
    rewrite ^/(.*)$ http://www.example.com/$1 permanent;
}

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

Quick Reference

Directive	Purpose	Example
server_name	Defines the domain to match	server_name example.com;
return 301	Sends permanent redirect	return 301 $scheme://www.example.com$request_uri;
$scheme	Preserves http or https	$scheme://www.example.com
$request_uri	Preserves full path and query	$request_uri

Key Takeaways

Use a separate server block for the non-www domain to handle redirection.

Use 'return 301' for efficient permanent redirects instead of 'rewrite'.

Always preserve the original request URI to keep user navigation intact.

Include '$scheme' to maintain the original protocol (http or https).

Test your configuration with 'nginx -t' and reload Nginx after changes.