Use Keep-Alive Headers to Reuse Connections

Web browsers commonly must make multiple requests to the same domain or web server to download information. In order to save time and resources, web browsers will ask websites to keep their connections alive so the web browser does not have to negotiate a new connection each time. Using the same connection to send multiple files or pieces of information to a visitor’s web browser can help improve website loading performance.

Web browsers ask websites to keep their connections open by sending the Keep-Alive Header along with their initial requests for website content.

Many web servers, such as Apache and NGINX, have Keep-Alive enabled by default. In some rare cases, Keep-Alive may be disabled to help manage large numbers of connections to a website, but it should be enabled when possible to help improve website loading performance.

The Keep-Alive Header does not apply to websites using HTTP/2. HTTP/2 achieves this same functionality by other means.