How to use keep-alive connections to improve performance

This article explains how to use keep-alive connections to improve performance in Apache.

How to enable keep-alive connections

Keep-alive connections handle many HTTP requests and responses over a single TCP connection. Keep-alive connections allow clients and servers to interact more efficiently and use less resources by not starting a new TCP connection every time a browser sends a request.

Many performance testing sites, such as GTMetrix, check to see if a site's keep-alive connections are enabled. If they are disabled, your site performance score suffers.

If keep-alive conections are disabled for your site, you can easily enable them. To do this, follow these steps:

1. Edit or create an .htaccess file in your site's document root directory.
2. Copy the following lines and paste them into the .htaccess file:

   <IfModule mod_headers.c>
       Header set Connection keep-alive
   </IfModule>
   

3. Save your changes to the .htaccess file. Keep-alive connections are now enabled.